Cover not available

In:Visually Situated Language Comprehension
Edited by Pia Knoeferle, Pirita Pyykkönen-Klauck and Matthew W. Crocker
[Advances in Consciousness Research 93] 2016
► pp. 151–184

Get fulltext from our e-platform
JBE logo with link
PDF logo with download linkDownload Book PDF
authorization required

Discourse level processing

Published online: 10 March 2016
DOI logo with link
https://doi.org/10.1075/aicr.93.06kai
This chapter provides an overview of how the visual-world eye-tracking paradigm has been used to investigate the processing and representation of discourse-level information. The chapter starts by reviewing some theoretical approaches to information structure, and then turns to visual-world experiments on the prosodic and syntactic reflexes of information structure, as well as the consequences of information structure for reference resolution. The notion of ‘prominence’ plays a central role in many of these investigations, in the shape of prosodic prominence (associated with new information), syntactic prominence (often associated with given or topical information) and representational prominence / accessibility in the domain of reference resolution. Comprehenders use prominence-related information to guide discourse-level aspects of processing, but prosodic prominence and syntactic prominence have different information-structural correlates. Furthermore, if we want to conceptualize reference resolution as a process sensitive to the prominence of mental representations, our view of what factors influence referential prominence needs to include not only entity-related factors (e.g. givenness), but also event-related factors (e.g. verb semantics and coherence relations between events). As a whole, the findings discussed in this chapter highlight the rapidity with which the human language processing system uses of discourse-level information, whether it be encoded in pitch accents, word order or the form of referring expressions. These findings suggest that discourse-level comprehension should not be relegated to a secondary stage of processing and instead occurs in tandem with other aspects of language comprehension, such as lexical access and syntactic processing.
References (113)
References
Allopenna, P.D., Magnuson, J.S., & Tanenhaus, M.K. (1998). Tracking the time course of spoken word recognition: Evidence for continuous mapping models. Journal of Memory and Language, 38, 419-439. Google Scholar logo with link to Google Scholar
Almor, A. (1999). Noun-phrase anaphora and focus: The informational load hypothesis. Psychological Review, 106(4), 748-765. Google Scholar logo with link to Google Scholar
Altmann, G.T.M. & Kamide, Y. 1999. Incremental interpretation at verbs: Restricting the domain of subsequent reference. Cognition, 73, 247-264. Google Scholar logo with link to Google Scholar
Altmann, G.T.M. (2004). Language-mediated eye movements in the absence of a visual world: The ‘blank screen paradigm’. Cognition, 93, 79-87 Google Scholar logo with link to Google Scholar
Ariel, M. (1990). Accessing NP antecedents. London: Routledge, Croom Helm.Google Scholar logo with link to Google Scholar
. (2001). Accessibility theory: An overview. In T. Sanders, J. Schilperoord, & W. Spooren (Eds.), Text representation, linguistic and psycholinguistic aspects (pp. 29-87). Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Arnold, J.E., & Tanenhaus, M.K. (2011). Disfluency effects in comprehension: How new information can become accessible. In E. Gibson & N. Perlmutter (Eds.), The processing and acquisition of reference. MIT Press. Google Scholar logo with link to Google Scholar
Arnold, J.E., Eisenband, J.G., Brown-Schmidt, S., & Trueswell, J.C. (2000). The immediate use of gender information: Eyetracking evidence of the time-course of pronoun resolution. Cognition, 76, B13-B26. Google Scholar logo with link to Google Scholar
Arnold, J.E., Wasow, T., Losongco, A., & Ginstrom, R. (2000). Heaviness vs. newness: The effects of structural complexity and discourse status on constituent ordering. Language, 76, 28-55 Google Scholar logo with link to Google Scholar
Arnold, J.E., Brown-Schmidt, S., & Trueswell, J.C. (2007). Children's use of gender and order-of-mention during pronoun comprehension. Language and Cognitive Processes, 22(4), 527-565. Google Scholar logo with link to Google Scholar
Beckman, M.E. (1996). The parsing of prosody. Language and Cognitive Processes, 11, 17-67. Google Scholar logo with link to Google Scholar
Beckman, M.E., & Ayers, G.M. (1997). Guidelines for ToBI labelling, vers 3.0. Ohio State University.Google Scholar logo with link to Google Scholar
Birch, S.L., Albrecht, J.E., & Myers, J.L. (2000). Syntactic focusing structures influence discourse processing. Discourse Processes, 30, 285-304. Google Scholar logo with link to Google Scholar
. (2009). Information structure and syntactic structure. Language and Linguistics Compass, 3/4, 1167-1187. Google Scholar logo with link to Google Scholar
Bolinger, D. (1986). Intonation and its parts: Melody in spoken English. Stanford: Stanford University Press.Google Scholar logo with link to Google Scholar
Brennan, S.E., Friedman, M.A., & Pollard, C.J. (1987). A centering approach to pronouns. In Proceedings of the 25th annual meeting of the Association for Computational Linguistics (pp. 155-162). Stanford, CA: Association for Computational Linguistics.
Brown-Schmidt, S. (2005) Language processing in conversation. Ph.D. Dissertation, University of Rochester.Google Scholar logo with link to Google Scholar
Brown-Schmidt, S., Byron, D.K., & Tanenhaus, M. (2005). Beyond salience: Interpretation of personal and demonstrative pronouns. Journal of Memory and Language, 53, 292-313. Google Scholar logo with link to Google Scholar
Büring, D. (1997). The meaning of topic and focus – The 59th Street Bridge accent. London: Routledge. Google Scholar logo with link to Google Scholar
Chafe, W.L. (1974). Language and consciousness. Language, 50, 111-133. Google Scholar logo with link to Google Scholar
. (1976). Givenness, contrastiveness, definiteness, subjects, topics, and point of view. In C. Li (Ed.), Subject and topic (pp. 25-55). New York: Academic Press.Google Scholar logo with link to Google Scholar
Chen, A., Den Os, E., & De Ruiter, J.P. (2007). Pitch accent type matters for online processing of information status: Evidence from natural and synthetic speech. The Linguistic Review, 24(2), 317-344. Google Scholar logo with link to Google Scholar
Chomsky, N. (1971). Deep structure, surface structure, and semantic interpretation. In D. Steinberg & L. Jacobovits (Eds.), Semantics (pp. 183-216). Cambridge: Cambridge University Press.Google Scholar logo with link to Google Scholar
Clark, H.H., & Clark, E.V. (1977). Psychology and language. New York: Harcourt Brace Jovanovich.Google Scholar logo with link to Google Scholar
Clark, H.H., & Haviland, S. (1977). Comprehension and the given-new contract. In R. Freedle (Ed.), Discourse production and comprehension (pp. 1-40). Hillsdale, NJ: Erlbaum.Google Scholar logo with link to Google Scholar
Clifton, C., & Frazier, L. (2004). Should given information come before new? Yes and no. Memory and Cognition, 32(6), 886-895. Google Scholar logo with link to Google Scholar
Colonna, S., Schimke, S., & Hemforth, B. (2010). Le rôle de la structure informationnelle dans l’interprétation d’une anaphore pronominale inter-phrastique. In F. Neveu at al. (Eds.), Congrès Mondial de Linguistique Française, 1489-1499.Google Scholar logo with link to Google Scholar
Cooper, R.M. (1974). The control of eye fixation by the meaning of spoken language: A new methodology for the real-time investigation of speech perception, memory, and language processing. Cognitive Psychology, 6, 84-107. Google Scholar logo with link to Google Scholar
Cowles, H.W. (2003). Processing information structure: Evidence from comprehension and production. Ph.D. dissertation, UCSD.Google Scholar logo with link to Google Scholar
Cowles, H.W., Walenski, M., & Kluender, R. (2007). Linguistic and cognitive prominence in anaphor resolution: Topic, constrastive focus and pronouns. Topoi, 26, 3-18. Google Scholar logo with link to Google Scholar
Crawley, R.J., & Stevenson, R.J. (1990). Reference in single sentences and in texts. Journal of Psycholinguistic Research, 19(3), 191-210. Google Scholar logo with link to Google Scholar
Cutler, A., & Fodor, J. (1979). Semantic focus and sentence comprehension. Cognition, 7, 49-59 Google Scholar logo with link to Google Scholar
Dahan, D., Tanenhaus, M.K., & Chambers, C.G. (2002). Accent and reference resolution in spoken-language comprehension. Journal of Memory and Language, 47, 292-314. Google Scholar logo with link to Google Scholar
Delin, J., & Oberlander, J. (1995). Syntactic constraints on discourse structure: The case of it-clefts. Linguistics, 33, 3. Google Scholar logo with link to Google Scholar
Dufter, A. (2009). Clefting and discourse organization: Comparing Germanic and Romance. In A. Dufter & D. Jacob (Eds.), Focus and background in romance languages (Studies in Language Companion Series 112). Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Ellert, M., Järvikivi, J., & Roberts, L. (2009) Information structure guides gaze behavior: Processing the German subject pronouns er and der in spoken discourse. Poster presented at 15th Annual Conference on Architectures and Mechanisms for Language Processing , Barcelona, Spain.
Engelhardt, P.E., Ferreira, F., & Patsenko, E.G. (2010). Pupillometry reveals processing load during spoken language comprehension. Quarterly Journal of Experimental Psychology, 63, 639-645. Google Scholar logo with link to Google Scholar
Féry, C. Skopeteas, S., & Hörnig, R, . (2010). Cross-linguistic comparison of prosody, syntax and information structure in a production experiment on localizing expressions. Transactions of the Philological Society, 108(3), 329-351 Google Scholar logo with link to Google Scholar
Foraker, S., & McElree, B. (2007). The role of prominence in pronoun resolution: Active versus passive representations. Journal of Memory and Language, 56(3), 357-383 Google Scholar logo with link to Google Scholar
Garnham, A. (2001). Mental models and the interpretation of anaphora. Hove: Psychology Press.Google Scholar logo with link to Google Scholar
Garvey, C., & Caramazza, A. (1974). Implicit causality in verbs. Linguistic Inquiry, 5, 459-464.Google Scholar logo with link to Google Scholar
Gleitman, L., January, D., Nappa, R. & Trueswell, J. (2007). On the give and take between event apprehension and utterance formulation. Journal of Memory and Language, 57, 544-569. Google Scholar logo with link to Google Scholar
Gordon, P.C., Grosz, B.J., & Gilliom, L.A. (1993). Pronouns, names, and the centering o attention in discourse. Cognitive Science, 17, 311-347. Google Scholar logo with link to Google Scholar
Green, M. & Jaggar, P. (2003). ‘Ex-situ and In-situ Focus in Hausa: Syntax, semantics and discourse.’ In Lecarme, J (Ed.), Research in afroasiatic grammar II. [CILT 241]. (pp. 187-213). Amsterdam: John Benjamins: Google Scholar logo with link to Google Scholar
Griffin, Z.M., & Bock, J.K. (2000). What the eyes say about speaking. Psychological Science, 11, 274-279. Google Scholar logo with link to Google Scholar
Gundel, J.K. (1974). The role of topic and comment in linguistic theory. Ph.D. dissertation, University of Texas at Austin.Google Scholar logo with link to Google Scholar
. (1988). Universals of topic-comment structure. In M. Hammond, E. Moravczik, & J. Wirth (Eds.), Studies in syntactic typology (pp. 209-239). Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Gundel, J.K., & Fretheim, T. (2004). Topic and focus. In G. Ward & L. Horn (Eds.), Handbook of pragmatics (Blackwell Handbooks in Linguistics). (pp.175-196). Oxford: Blackwell.Google Scholar logo with link to Google Scholar
Gundel, J.K., Hedberg, N., & Zacharski, R. (1993). Cognitive status and the form of referring expressions in discourse. Language, 69, 274-307. Google Scholar logo with link to Google Scholar
Gussenhoven, C. (1983). Focus, mode, and nucleus. Journal of Linguistics, 19, 377-417. Google Scholar logo with link to Google Scholar
Halliday, M. (1967). Notes on transitivity and theme in English. Part 1 and 2. Journal of Linguistics, 3, 37-81; 199-244. Google Scholar logo with link to Google Scholar
Hartshorne, Joshua K., Nappa, R., & Snedeker, J. (in press). Development of the first-mention bias. Journal of Child Language.
Haviland, S.E., & Clark, H.H. (1974). What's new? Acquiring new information as a process in comprehension. Journal of Verbal Learning and Verbal Behavior, 13, 512-521. Google Scholar logo with link to Google Scholar
Hedberg, N. (1990). Discourse pragmatics and cleft sentences in English. Ph.D dissertation, Universitiy of Minnesota.Google Scholar logo with link to Google Scholar
. (2000). The referential status of clefts. Language, 76, 891-920. Google Scholar logo with link to Google Scholar
Hornby, P.A. (1974). Surface structure and presupposition. Journal of Verbal Learning and Verbal Behavior, 13, 530-538. Google Scholar logo with link to Google Scholar
Huang, Y., & Snedeker, J. (2009). Online interpretation of scalar quantifiers: Insight into the semantics–pragmatics interface. Cognitive Psychology, 58(3), 376-415. Google Scholar logo with link to Google Scholar
Hwang, Heeju, & Kaiser, Elsi. (2014). The role of the verb in grammatical function assignment in English and Korean. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40, 1363-1376. Google Scholar logo with link to Google Scholar
Jackendoff, R. (1972). Semantic interpretation in generative grammar. Cambridge, MA: MIT PressGoogle Scholar logo with link to Google Scholar
Järvikivi, J., Van Gompel, R.P.G., Bertram, R., & Hyönä, J. (2005). Ambiguous pronoun resolution: Contrasting the first-mention and subject preference accounts. Psychological Science, 16, 260-264. Google Scholar logo with link to Google Scholar
Kaiser, E., & Trueswell, J.C. (2008) Interpreting pronouns and demonstratives in Finnish: Evidence for a form-specific approach to reference resolution. Language and Cognitive Processes, 23(5), 709-748. Google Scholar logo with link to Google Scholar
. (2004) The role of discourse context in the processing of a flexible word-order language. Cognition, 94(2), 113-147. Google Scholar logo with link to Google Scholar
Kaiser, E. (2009). Effects of anaphoric dependencies and semantic representations on pronoun interpretation. In S.L. Devi, A. Branco, & R. Mitkov (Eds.), Anaphora processing and applications (pp.121-130). Heidelberg: Springer. Google Scholar logo with link to Google Scholar
Kaiser, E., Runner, J.T., Sussman, R.S., & Tanenhaus. M.K. (2009). Structural and semantic constraints on the resolution of pronouns and reflexives. Cognition, 112, 55-80. Google Scholar logo with link to Google Scholar
Kaiser, Elsi. (2011a). Focusing on pronouns: Consequences of subjecthood, pronominalisation, and contrastive focus. Language and Cognitive Processes, 26, 1625-1666. Google Scholar logo with link to Google Scholar
. (2011b). Salience and contrast effects in reference resolution: The interpretation of Dutch pronouns and demonstratives, Language and Cognitive Processes, 26, 1587-1624. Google Scholar logo with link to Google Scholar
Kamide, Y., Altmann, G.T.M., & Haywood, S. (2003). The time-course of prediction in incremental sentence processing: Evidence from anticipatory eye-movements. Journal of Memory and Language, 49, 133-59. Google Scholar logo with link to Google Scholar
Kehler, A. (2002). Coherence, reference, and the theory of grammar. Stanford: CSLI Publications.Google Scholar logo with link to Google Scholar
Kehler, A., Kertz, L., Rohde, H., & Elman, J. (2008). Coherence and coreference revisited. Journal of Semantics (Special Issue on Processing Meaning), 25(1), 1-44.Google Scholar logo with link to Google Scholar
Kiss, K.E. (1998). Identificational focus versus information focus. Language, 74, 245-273. Google Scholar logo with link to Google Scholar
Knoeferle, P., Crocker, M.W., Scheepers, C., & Pickering, M.J. (2005). The influence of the immediate visual context on incremental thematic role assignment: Evidence from eye-movements in depicted events. Cognition, 95, 95-127. Google Scholar logo with link to Google Scholar
Koornneef, A.W., & Van Berkum, J.J.A. (2006). On the use of verb-based implicit causality in sentence comprehension: Evidence from self-paced reading and eye tracking. Journal of Memory and Language, 54, 445-465. Google Scholar logo with link to Google Scholar
Ladd, D.R. (1996). Intonational phonology. Cambridge: Cambridge University Press.Google Scholar logo with link to Google Scholar
Lambrecht, K. (1994). Information structure and sentence form: Topic, focus, and the mental representation of discourse referents. Cambridge: Cambridge University Press. Google Scholar logo with link to Google Scholar
. (2001). A framework for the analysis of cleft constructions. Linguistics, 39, 463-516. Google Scholar logo with link to Google Scholar
Magnuson, J.S., Dixon, J.A., Tanenhaus, M.K., & Aslin, R.N. (2007). The dynamics of lexical competition during spoken word recognition. Cognitive Science, 31, 133-156. Google Scholar logo with link to Google Scholar
Myhill, J. (1992). Typological discourse analysis. Oxford: Basil Blackwell.Google Scholar logo with link to Google Scholar
Pierrehumbert, J., & Hirschberg, J. (1990). The meaning of intonational contours in the interpretation of discourse. In P.R. Cohen, J. Morgan, & M.E. Pollack (Eds.), Intentions in communication (pp. 271-311). Cambridge, MA: MIT Press.Google Scholar logo with link to Google Scholar
Prince, E.F. (1978). A comparison of WH-clefts and IT-clefts in discourse. Language, 54, 883-906. Google Scholar logo with link to Google Scholar
. (1992). The ZPG letter: Subjects, definiteness, and information status. In S. Thompson & W. Mann (Eds.), Discourse description: Diverse analyses of a fund-raising text (pp. 295-325). Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Pyykkönen, P., & Järvikivi, J. (2010). Activation and persistence of implicit causality information in spoken language comprehension. Experimental Psychology, 57 (1), 5-16. Google Scholar logo with link to Google Scholar
Pyykkönen, P., Matthews, D., & Järvikivi, J. (2010). Three-year-olds are sensitive to semantic prominence during online language comprehension: A visual world study of pronoun resolution. Language and Cognitive Processes, 25, 115-129. Google Scholar logo with link to Google Scholar
Reinhart, T. (1982). Pragmatics and linguistics: An analysis of sentence topics. University of Indiana Linguistics Club. (also Philosophica 1981, 27, 53-94).Google Scholar logo with link to Google Scholar
Rochemont, M. (1986). Focus in generative grammar. Amsterdam: John Benjamins. Google Scholar logo with link to Google Scholar
Rooth, M. (1992). A Theory of focus interpretation. Natural Language Semantics, 1, 75-116. Google Scholar logo with link to Google Scholar
Schwarzschild, R. (1999). GIVENness, Avoid F and other constraints on the placement of focus. Natural Language Semantics, 7, 141-177. Google Scholar logo with link to Google Scholar
Sedivy, J., Tanenhaus, M., Chambers, C., & Carlson, G. (1999). Achieving incremental semantic interpretation through contextual representation. Cognition, 71, 109-147. Google Scholar logo with link to Google Scholar
Sekerina, I.E. & Trueswell, J.C. (2012). Interactive processing of contrastive expressions by Russian children. First Language 32: 63-87. Google Scholar logo with link to Google Scholar
Selkirk, E.O. (1995). Sentence prosody: Intonation, stress, and phrasing. In J.A. Goldsmith (Ed.), The handbook of phonological theory (pp. 550-569). Oxford, UK: Blackwell.Google Scholar logo with link to Google Scholar
Sgall, P., & Hajicova, W.E. (1977). Focus on focus. The Prague Bulletin of Mathematical Linguistics, 28: 5-54.Google Scholar logo with link to Google Scholar
Song, H., & Fisher, C. (2005). Who’s ‘she’? Discourse prominence influences preschoolers comprehension of pronouns. Journal of Memory and Language, 52, 29-57. Google Scholar logo with link to Google Scholar
Spivey, M.J., Richardson, D.C., & Fitneva, S.A. (2004). Thinking outside the brain: Spatial indices to visual and linguistic Information. In J. Henderson & F. Ferreira (Eds.), Interfacing language, vision, and action (pp. 161-190). San Diego, CA: Academic Press.Google Scholar logo with link to Google Scholar
Steedman, M. (2000). Information structure and the syntax–phonology interface. Linguistic Inquiry, 31, 649-689. Google Scholar logo with link to Google Scholar
Strube, M., & Hahn, U. (1996). Functional centering. In Proceedings of the 34th annual meeting of the Association for Computational Linguistics (pp. 270-277), Santa Cruz, CA.
. (1999). Functional centering: Grounding referential coherence in information structure. Computational Linguistics, 25(3), 309-344.Google Scholar logo with link to Google Scholar
Sturt, P., Sanford, A.J., Stewart, A., & Dawydiak, E. (2004). Linguistic focus and good-enough representations: An application of the change-detection paradigm. Psychonomic Bulletin and Review, 11, 882-888. Google Scholar logo with link to Google Scholar
Tanenhaus, M.K. (2007). Spoken language comprehension: insights from eye movements. In G. Gaskell (Ed.), Oxford handbook of psycholinguistics (pp. 309-326). Oxford: Oxford University Press.Google Scholar logo with link to Google Scholar
Tanenhaus, M.K., Spivey-Knowlton, M., Eberhard, K.M., & Sedivy, J.C. (1995). Integration of visual and linguistic information in spoken language comprehension. Science, 268, 1632-1634. Google Scholar logo with link to Google Scholar
Tavano, E., & Kaiser, E. (2008). Effects of stress and coherence on pronoun interpretation. Poster presented at the 21st Annual CUNY Conference on Human Sentence Processing , University of North Carolina-Chapel Hill.
Vallduví, E., & Vilkuna, M. (1998). On rheme and kontrast. In P. Culicover & M. Louise (Eds.), The limits of syntax. Syntax and semantics 29 (pp. 79-108). New York: Academic Press.Google Scholar logo with link to Google Scholar
Vallduvi. E. (1990). The information component. Ph.D dissertation, University of Pennsylvania.Google Scholar logo with link to Google Scholar
Van de Velde, M., Meyer, A.S., & Konopka, A.E. (2014). Message formulation and structural assembly: Describing "easy" and "hard" events with preferred and dispreferred syntactic structures. Journal of Memory and Language, 71(1), 124-144. Google Scholar logo with link to Google Scholar
Venditti, J.J., Stone, M., Nanda, P., & Tepper, P. (2001). Discourse constraints on the interpretation of nuclear-accented pronouns. In Proceedings of the 2002 International Conference on Speech Prosody , Aix-en-Provence, France.
Vilkuna, M. (1989) Free word order in finnish: Its syntax and discourse functions. Helsinki: Finnish Literature Society.Google Scholar logo with link to Google Scholar
Ward, G. (1985). The semantics and pragmatics of preposing. Ph.D dissertation, University of Pennsylvania.Google Scholar logo with link to Google Scholar
Ward, P., & Sturt, P. (2007). Linguistic focus and memory: An eye-movement study. Memory and Cognition, 35, 73-86. Google Scholar logo with link to Google Scholar
Weber, A., Braun, B., & Crocker, M.W. (2006). Finding referents in time: Eye-tracking evidence for the role of contrastive accents. Language and Speech, 49, 367-392. Google Scholar logo with link to Google Scholar
Weber, A., Grice, M., & Crocker, M.W. (2006). The role of prosody in the interpretation of structural ambiguities: A study of anticipatory eyemovements. Cognition, 99, B63-B72. Google Scholar logo with link to Google Scholar
Wilson. F. (2009). Processing at the syntax-discourse interface in second language acquisition. Ph.D. dissertation, University of Edinburgh.Google Scholar logo with link to Google Scholar
Yee, E., Heller, D., & Sedivy, J.C. (2009). On the relationship between eye-movements and activation: Active vs. passive tasks during ambiguous pronoun resolution. Poster presented at the 22nd Annual CUNY Conference on Human Sentence Processing .
Zimmer, H.D., & Engelkamp, J. (1981). The given-new structure of cleft sentences and their influence on picture viewing. Psychological Research, 43, 375-389. Google Scholar logo with link to Google Scholar
Cited by (1)

Cited by one other publication

Gračanin-Yuksek, Martina, Sol Lago, Duygu Fatma Şafak, Orhan Demir & Bilal Kırkıcı
2017. The Interaction of Contextual and Syntactic Information in the Processing of Turkish Anaphors. Journal of Psycholinguistic Research 46:6 ► pp. 1397 ff. DOI logo

This list is based on CrossRef data as of 10 december 2025. Please note that it may not be complete. Sources presented here have been supplied by the respective publishers. Any errors therein should be reported to them.

Mobile Menu Logo with link to supplementary files background Layer 1 prag Twitter_Logo_Blue