The rise of scientific inquiry focusing on bilingualism over the past few decades has also borne witness to an increase in the study of individuals and communities who speak a native language that is not the sociolinguistically dominant language of the environment in which they grew up. While it is common practice to refer to these diverse groups and individuals as “heritage speakers”, it is unclear whether it is appropriate to classify all of them under the same terminology. In this chapter, we take a closer look at three different groups: (i) children, (ii) young adults, and (iii) elderly, moribund bilinguals who have all been referred to as heritage speakers in the literature. After exploring aspects of phonological, (morpho)syntactic, and semantic/pragmatic developments, we show that a great deal of symmetry exists between them, thus justifying the cohesive, overarching label of “heritage speakers” to all three sub-groups. Finally, we outline what this broader definition of heritage speakers means for long-standing debates in the literature, such as those that concern the acquisition, development, and maintenance of the heritage grammar across the lifespan.
Forthcoming). Introduction to the special issue/Heritage language studies and early child bilingualism research: Understanding the connection. International Journal of Bilingualism.
Albirini, A., Benmamoun, E., & Saadah, E.
(2011) Grammatical features of Egyptian and Palestinian Arabic heritage speakers’ oral production. Studies in Second Language Acquisition, 33(02), 273–303.
(2001) Bilingual acquisition and separation of linguistic codes: Ergativity in Basque versus accusativity in Spanish. In K. E. Nelson, A. Aksu-Koç, & C. E. Johnson (Eds.), Children’s language (pp. 27–48). Mahwah, NJ: Lawrence Erlbaum Associates.
Alvord, S., & Rogers, B.
(2014) Miami-Cuban Spanish vowels in contact. Sociolinguistic Studies, 8(1), 139–170.
Amengual, M.
(2012) Interlingual influence in bilingual speech: Cognate status effect in a continuum of bilingualism. Bilingualism: Language and Cognition, 15(3), 517–530.
Au, T. K. F., Knightly, L. M., Jun, S. A., & Oh, J. S.
(2002) Overhearing a language during childhood. Psychological science, 13(3), 238–243.
Bayram, F., Rothman, J., Iverson, M., Kupisch, T., Miller, D., Puig Mayenco, E., & Westergaard, M.
(2017) Differences in use without deficiencies in competence: Passives in the Turkish and German of Turkish heritage speakers in Germany. International Journal of Bilingual Education and Bilingualism, 1–21.
Bayram, F., Pascual y Cabo, D., & Rothman, J.
Forthcoming). Cross-generational attrition contributions to heritage speaker competence. In B. Köpke & M. S. Schmid Eds. The Cambridge handbook of attrition Cambridge Cambridge University Press
Berend, N., & Jedig, H.
(1991) Deutsche Mundarten in der Sowjetunion: Geschichte der Forschung und Bibliographie. Marburg: N. G. Elwert.
(2004) Growing syntactic structure and code-mixing in the weaker language: The Ivy Hypothesis. Bilingualism: Language and Cognition, 7, 49–70.
Boas, H.
(2009) The life and death of Texas German (Publication of the American Dialect Society, 93). Durham, NC: Duke University Press.
Bullock, B. E.
(2009) Prosody in contact in French: A case study from a heritage variety in the USA. International Journal of Bilingualism, 13(2), 165–194.
Bullock, B. E., & Gerfen, C.
(2004) Phonological convergence in a contracting language variety. Bilingualism: Language and Cognition, 7(2), 95–104.
Burling, R.
(1959) Language development of a Garo and English speaking child. Word, 15, 45–68.
Cuza, A.
(2013) Crosslinguistic influence at the syntax proper: Interrogative subject–verb inversion in heritage Spanish. International Journal of Bilingualism, 17(1), 1–26.
de Bot, K., & Stoessel, S.
(2000) In search of yesterday’s words: Reactivating a long forgotten language. Applied Linguistics, 21, 364–384.
De Houwer, A.
(1995) Bilingual language acquisition. In P. Fletcher & B. MacWhinney (Eds.), The handbook of child language (pp. 219–250). Oxford: Blackwell.
De Houwer, A.
(2002) How different are monolingual and bilingual acquisition?Ilha do Desterro [
A Journal of English Language, Literatures in English and Cultural Studies
], 43, 127–148. Available at [URL]
Déhe, N.
Forthcoming). The intonation of polar questions in North American (‘heritage’) Icelandic. Journal of Germanic Linguistics.
Dorian, N.
(1977) The problem of the semi-speaker in language death. IJSL, 12, 23–32.
Dorian, N.
(1981) Language death: The life cycle of a Scottish Gaelic dialect. Philadelphia, PA: University of Pennsylvania Press.
Egger, E., Hulk, A., & Tsimpli, I.
Forthcoming). Crosslinguistic influence in the discovery of gender: The case of Greek-Dutch bilingual children. Bilingualism: Language and Cognition.
Ezeizabarrena, M. J.
(2002) Root infinitives in two pro-drop languages. In A. Pérez-Leroux, & J. Liceras (Eds.), The acquisition of Spanish syntax. The L1/l2 connection (pp. 35–65). Dordrecht: Kluwer.
Flores, C., & Barbosa, P.
(2014) When reduced input leads to delayed acquisition: A study on the acquisition of clitic placement by Portuguese heritage speakers. International Journal of Bilingualism, 18(3), 304–325.
Flores, C., & Rato, A.
(2016) Global accent in the Portuguese speech of heritage returnees. Heritage Language Journal, 13(2), 161–183.
(1989) Early bilingual development: One language or two?Journal of Child Language, 16, 161–79.
Goral, M.
(2014) Bilingualism, language, and aging. In J. Altarriba & L. Isurin (Eds.), Memory, language and bilingualism: Theoretical and applied approaches (pp. 188–210). Cambridge: Cambridge University Press.
Goral, M., Spiro III, A., Albert, M. L., Obler, L. K., & Connor, L. T.
(2000) The acquisition of the determiner phrase in bilingual and second language French. Bilingualism: Language and Cognition, 3(3), 263–280.
Granfeldt, J.
Forthcoming). The development of gender in simultaneous and successive bilingual acquisition of French – Evidence for AOA and input effects. Bilingualism: Language and Cognition.
Hansegård, N. .
(1968) Tvåspråkighet eller halvspråkighet? Stockholm: Aldus/Bonnier.
(2004) The acquisition of the French DP in a bilingual context. In P. Prévost & J. Paradis (Eds.), The acquisition of French in different contexts. Focus on functional categories (pp. 243–274). Amsterdam: John Benjamins.
Hulk, A., & Müller, N.
(2000) Cross-linguistic influence at the interface between syntax and pragmatics. Bilingualism: Language and Cognition, 3, 227–244.
Hulk, A., & van der Linden, E.
(2010) How vulnerable is gender? In P. Guijarro-Fuentes & L. Domínguez (Eds.), New directions in language acquisition: Romance languages in the generative perspective (pp. 107–132). Newcastle upon Tyne: Cambridge Scholars.
Ingram, D.
(1981) Some characteristics of delayed phonological systems. In H. Winitz (Ed.), Native language and foreign language acquisition (pp. 138–143). New York, NY: New York Academy of Science.
Ivanova, I., Murillo, M., Montoya, R. I., & Gollan, T. H.
(2014) Interpretation of anaphoric subject pronouns in heritage Russian. In R. T. Miller, K. I. Martin, C. M. Eddington, A. Henery, N. Marcos Miguel, A. M. Tseng, A. Tuninetti, & D. Walter (Eds.), Selected Proceedings of the 2012 Second Language Research Forum (pp. 145–154). Somerville, MA: Cascadilla Proceedings Project.
(1994) The Volga-German dialect of Schoenchen, Kansas. Unpublished PhD dissertation, University of Kansas.
Joo, H.-A., Schwarz, L., & Page, B. R.
to appear). Non-convergence and divergence in bilingual phonological and phonetic systems: Low back vowels in Moundridge Schweitzer German and English. Journal of Language Contact.
Keel, W. D.
(2015) Noun phrase case shift in Volga German varieties on the Great Plains of Kansas. In B. R. Page, & M. T. Putnam (Eds.), Moribund Germanic heritage languages in North America: Theoretical perspectives and empirical findings (pp. 133–152). Leiden: Brill.
Kehoe, M.
(2002) Developing vowel systems as a window to bilingual phonology. International Journal of Bilingualism, 6, 315–334.
Kehoe, M.
Forthcoming). The development of rhotics: A comparison of monolingual and bilingual children. Bilingualism: Language and Cognition.
Kehoe, M., Lleó, C., & Rakow, M.
(2004) Voice onset time in bilingual German-Spanish children. Bilingualism: Language and Cognition, 7(1), 71–88.
(2009) Binding interpretation of anaphors in Korean heritage bilingual speakers. Language Acquisition, 16, 3–35.
Kupisch, T.
(2007) Determiners in bilingual German-Italian children: What they tell us about the relation between language influence and language dominance. Bilingualism: Language and Cognition, 10(1), 57–78.
Kupisch, T.
(2012) Generic subjects in the Italian of early German-Italian bilinguals and German learners of Italian as a second language. Bilingualism: Language and Cognition, 15(4), 736–756.
Kupisch, T.
(2013) A new term for a better distinction? A view from the higher end of the proficiency. Theoretical Linguistics, 39, 203–214.
Kupisch, T., & Lleó, C.
(2017) Voice Onset Time in German-Italian simultaneous bilinguals: Evidence on crosslanguage influence and markedness. In M. Yavas, M. Kehoe, & W. Cardono (Eds.), Romance-Germanic Bilingual Phonology (pp. 79–98). Leeds: Equinox.
Kupisch, T., & Pierantozzi, C.
(2010) Interpreting definite plural subjects: A comparison of German and Italian monolingual and bilingual children. In K. Franich, K. M. Iserman, & L. Keil (Eds.), 34th Boston University Conference on Language and Development (pp. 245–254), Somerville, MA: Cascadilla Press.
Kupisch, T., Barton, D., Hailer, K., Lein, T., Stangen, I., & van de Weijer, J.
(2014a) Foreign accent in adult simultaneous bilinguals?Heritage Language Journal 11(2), 123–150.
Kupisch, T., Barton, D., Lein, T., Schröder, J., Stangen, I., & Stöhr, A.
(2014b) Acquisition outcomes across domain in adult heritage speakers of French. Journal of French Language Studies, 24(3), 347–376.
Kupisch, T., Belikova, A., Özçelik, Ö., Stangen, I., & White, L.
(2002) Gender in monolingual and bilingual first language acquisition: Comparing Italian and French. Lingue e Linguaggio, 1, 107–149.
Kupisch, T., & Rothman, J.
(2016) Terminology matters!: Why difference is not incompleteness and how early child bilinguals are heritage speakers. International Journal of Bilingualism.
Larsson, I., & Johannesen, J. B.
(2015) Incomplete acquisition and verb placement in heritage Scandinavian. In B. R. Page & M. T. Putnam (Eds.), Moribund Germanic heritage languages in North America: Theoretical perspectives and empirical findings (pp. 153–189). Leiden: Brill.
Leal, T., J. Rothman, & R. Slabakova
(2014) A rare structure at the syntax-discourse interface: heritage and Spanish-dominant native speakers weigh in. Language Acquisition, 21(4), 411–429.
Lein, T., Kupisch, T., & van de Weijer, J.
(2017) Voice onset time and global foreign accent in German-French simultaneous bilinguals during adulthood. International Journal of Bilingualism, 20(6), 132–149.
Leopold, W.
(1953) Patterning in children’s language learning. Language Learning, 5, 1–14.
Lleó, C.
(2016) Bilingualism and child phonology. Oxford Handbooks Online. [URL]
Lleó, C.
Forthcoming). Aspects of the phonology of Spanish as a heritage language. Bilingualism: Language and Cognition.
Lleó, C., Kuchenbrandt I., Kehoe, M., & Trujillo, C.
(2016) Grammatical gender in American Heritage Norwegian language: Stability or attrition?Frontiers in Psychology, 7, 344.
Meisel, J.
(1986) Word order and case marking in early child language. Evidence from simultaneous acquisition of two first languages: French and German. Linguistics, 24(1), 123–184.
Meisel, J.
(1989) Early differentiation of languages in bilingual children. In K. Hyltenstam, & L. Obler (Eds.), Bilingualism across the lifespan: Aspects of acquisition, maturity, and loss. (pp. 13–40). Cambridge: Cambridge University Press.
Meisel, J.
(1990) Word order and case marking in early child language. Evidence from the simultaneous acquisition of two first languages. In J. Meisel (Ed.), Two first languages: Early grammatical development in bilingual children (pp. 5–22). Dordrecht: Foris.
(2004) The bilingual child. In T. K. Bhatia & W. C. Ritchie (Eds.), The handbook of bilingualism (pp. 91–112). Oxford: Blackwell.
Meisel, J.
(2007) On autonomous syntactic development in multiple first language acquisition. In H. Caunt-Nulton, S. Kulatilake, & I.-H. Woo (Eds.), Proceedings of the 31st Boston University Conference on language development (pp. 26–45). Somerville, MA: Cascadilla Press.
Meisel, J.
(2014) Heritage language learners: Incomplete acquisition of grammar in early childhood. In A. Enrique-Arias, M. J. Gutiérrez, A. Landa, & F. Ocampo (Eds.), Perspectives in the study of Spanish language variation (pp. 429–454). Santiago de Compostela: Universidad de Santiago de Compostela.
Montrul, S.
(2002) Competence and performance differences between monolinguals and 2nd generation bilinguals in the Tense/Aspect domain. In J. F. Lee, K. Geeslin, & J. C. Clements (Eds.), Structure, meaning, and acquisition in Spanish: Papers from the 4th Hispanic Linguistics Symposium (pp. 93–114). Somerville, MA: Cascadilla.
Montrul, S.
(2004) Subject and object expression in Spanish heritage speakers: A case of morphosyntactic convergence. Bilingualism: Language and Cognition, 7(2), 125–142.
(2016) The acquisition of heritage languages. Cambridge: Cambridge University Press.
Montrul, S., & Ionin, T.
(2010) Transfer effects in the interpretation of definite articles by Spanish heritage speakers. Bilingualism: Language and Cognition, 13(4), 449–473.
Montrul, S., & Sánchez-Walker, N.
(2013) Differential object marking in child and adult Spanish heritage speakers. Language Acquisition, 20(2), 109–132.
Montrul, S., Foote, R., & Perpiñan, S.
(2008) Gender agreement in adult second language learners and Spanish heritage speakers: The effects of age and context of acquisition. Language Learning, 58(3), 503–553.
Montrul, S., Bhatt, R., & Girju, R.
(2015) Differential object marking in Spanish, Hindi, and Romanian as heritage languages. Language, 91(3), 564–610.
Müller, N.
(1993) Komplexe Sätze: Der Erwerb von COMP und von Wortstellungsmustern bei bilingualen Kindern (französisch/deutsch). Tübingen: Narr.
Müller, N., & Hulk, A.
(2001) Crosslinguistic influence in bilingual language acquisition: Italian and French as recipient languages. Bilingualism: Language and Cognition, 4, 1–21.
Nicoladis, E.
(2006) Cross-linguistic transfer in adjective-noun strings by preschool bilingual children. Bilingualism: Language and Cognition, 9, 15–32.
Oh, J., Jun, S.-A., Knightly, L., & Au, T.
(2003) Holding on to childhood language memory. Cognition, 86, B53–B64.
Page, B. R., & Putnam, M. T.
(Eds.) (2015) Moribund Germanic heritage languages in North America: Theoretical perspectives and empirical findings. Leiden: Brill.
Paradis, J., & Genesee, F.
(1996) Syntactic acquisition in bilingual children: Autonomous or interdependent?Studies in Second Language Acquisition, 18, 1–25.
Paradis, J., & Navarro, S.
(2003) Subject realization and crosslinguistic interference in the bilingual acquisition of Spanish and English: what is the role of input?Journal of Child Language, 30, 371–393.
Pascual y Cabo, D.
(2013) Agreement reflexes of emerging optionality in heritage speaker Spanish. Unpublished PhD dissertation, University of Florida.
Pascual y Cabo, D., & Gómez Soler, I.
(2015) Preposition stranding in Spanish as a heritage language. Heritage Language Journal, 12(2), 186–209.
Pascual y Cabo, D., & Rothman, J.
(2012) The (il)logical problem of heritage speaker bilingualism and incomplete acquisition. Applied Linguistics, 33(4), 1–7.
Pérez-Leroux, A., Pirvulescu, M., Roberge, I.
(2009) Bilingualism as a window into the language faculty: The acquisition of objects in French-speaking children in bilingual and monolingual contexts. Bilingualism: Language and Cognition, 12(1), 1–16.
Pires, A., & Rothman, J.
(2009) Disentangling sources of incomplete acquisition: An explanation for competence divergence across heritage grammars. International Journal of Bilingualism, 13(2), 211–238.
Platzack, C.
(2001) The vulnerable C-domain. Brain and Language, 77, 364–377.
Polinsky, M.
(2006) Incomplete acquisition: American Russian. Journal of Slavic Linguistics, 14(2), 191–262.
Polinsky, M.
(2011) Reanalysis in adult heritage language. Studies in Second Language Acquisition, 33(2), 305–328.
Puig-Mayenco, E., Miller, D., & Rothman, J.
(2016) Language dominance affects bilingual competence and processing: Evidence from a bi-directional study from Catalan-Spanish bilinguals. Paper presented at: BUCLD, 41st Boston University Conference on Language Development, Boston, MA.
(2015) Minimizing (interface) domains: The loss of long-distance binding in North American Icelandic. In B. R. Page & M. T. Putnam (Eds.), Researching moribund Germanic heritage languages: Theoretical challenges and empirical findings (pp. 203–223). Leiden: Brill.
(2014) On the status of the phoneme /b/ in heritage speakers of Spanish. Sintagma, 26, 37–54.
Rinke, E., & Flores, C.
(2014) Morphosyntactic knowledge of clitics by Portuguese heritage bilinguals. Bilingualism: Language and Cognition, 17(4), 681–699.
Rodina, Y., & Westergaard, M.
(2017) Grammatical gender in bilingual Norwegian–Russian acquisition: The role of input and transparency. Bilingualism: Language and Cognition, 20(1), 197–214.
Ronquest, R.
(2012) An acoustic analysis of heritage Spanish vowels. Unpublished PhD dissertation, Indiana University.
Ronquest, R.
(2013) An acoustic examination of unstressed vowel reduction in heritage Spanish. In C. Howe, S. E. Blackwell, & M. Lubbers Quesada (Eds.), Selected proceedings of the 15th Hispanic Linguistics Symposium (pp. 157–171). Somerville, MA: Cascadilla Proceedings Project.
(2007) Heritage speaker competence differences, language change and input type: Inflected infinitives in heritage Brazilian Portuguese. International Journal of Bilingualism, 11, 359–389.
Rothman, J.
(2009) Understanding the nature and outcomes of early bilingualism: Romance languages as heritage languages. International Journal of Bilingualism, 13, 155–163.
Rothman, J., & Treffers-Daller, J.
(2014) A prolegomenon to the construction of the native speaker: Heritage speaker bilinguals are natives too!Applied Linguistics, 35(1), 93–98.
(1993) The weaker language in bilingual Swedish–French children. In K. Hyltenstam, & A. Viberg (Eds.), Progression and regression in language: Sociocultural, neuropsychological and linguistic perspectives. Cambridge: Cambridge University Press.
Schmid, M. S.
(2011) Language attrition. Cambridge: Cambridge University Press.
Schmid, M. S., & Köpke, B.
(2007) Bilingualism and attrition. In B. Köpke, M. S. Schmid, M. C. J. Keijzer, & S. Dostert (Eds.), Language attrition: Theoretical perspectives (pp. 1–7). Amsterdam: John Benjamins.
Seliger, H. W., & Vago, R. M.
(1991) The study of first language attrition: An overview. In H. W. Seliger & R. M. Vago, First language attrition (pp. 3–15). Cambridge: Cambridge University Press.
Serratrice, L.
(2007) Referential cohesion in the narratives of bilingual English-Italian children and monolingual peers. Journal of Pragmatics, 29(6), 1058–1087.
Serratrice, L., Sorace, A., Filiaci, F., & Baldo, M.
(2009) Bilingual children’s sensitivity to specificity and genericity: Evidence from metalinguistic awareness. Bilingualism: Language and Cognition, 12, 239–257.
Silva-Corvalán, C.
(1994) Language contact and change: Spanish in Los Angeles. Oxford: Oxford University Press.
Sorace, A.
(2004) Native language attrition and developmental instability at the syntax-discourse interface: Data, interpretations, and methods. Bilingualism: Language and Cognition, 7, 143–145.
(2009) Internal and external interfaces in bilingual language development: Beyond structural overlap. International Journal of Bilingualism, 13, 1–16.
Stangen, I., Kupisch, T., Proietti Ergün, A. L., & Zielke, M.
(2015) Foreign accent in heritage speakers of Turkish in Germany. In H. Peukert (Ed.), Transfer effects in multilingual language development (pp. 87–108). Amsterdam: John Benjamins.
Vihman, M.
(2015) Prosodic structures and templates in bilingual phonological development. Bilingualism: Language and Cognition, 19(1), 1–20.
Villegas Erce, Á.
(2014) The role of L2 English immersion in the processing of L1 Spanish sentence complement/relative clause ambiguities. Unpublished PhD dissertation, The Pennsylvania State University.
Virtanen, R.
(1979) The Finnish language in America. Scandinavian Studies, 51(2), 146–161.
Vogel, I.
(1975) One system or two? An analysis of a two-year-old Romanian-English bilingual’s phonology. Papers and Reports on Child Language Development, 9, 43–62.
Volterra, V., & Taeschner, T.
(1978) The acquisition and development of language by bilingual children. Journal of Child Language, 5, 311–326.
2020. From Bidialectal to Bilingual. American Speech 95:4 ► pp. 485 ff.
Bousquette, Joshua & Michael T. Putnam
2020. Redefining Language Death: Evidence From Moribund Grammars. Language Learning 70:S1 ► pp. 188 ff.
D'Alessandro, Roberta, David Natvig & Michael T. Putnam
2021. Addressing Challenges in Formal Research on Moribund Heritage Languages: A Path Forward. Frontiers in Psychology 12
Dehé, Nicole & Tanja Kupisch
2022. Prepositional phrases and case in North American (heritage) Icelandic. Nordic Journal of Linguistics 45:3 ► pp. 254 ff.
Dávila-Montes, José & Lyon Rathbun
2020. La Perastories: cognitive and cultural alignment of narrative production by bilinguals in the U.S. – Mexican borderlands. Language and Intercultural Communication 20:3 ► pp. 240 ff.
Flores, Cristina
2020. Attrition and Reactivation of a Childhood Language: The Case of Returnee Heritage Speakers. Language Learning 70:S1 ► pp. 85 ff.
Flores, Cristina & Esther Rinke
2020. The relevance of language-internal variation in predicting heritage language grammars. Bilingualism: Language and Cognition 23:1 ► pp. 25 ff.
Giannakou, Aretousa
2023. Anaphora resolution and age effects in Greek-Spanish bilingualism: Evidence from first-generation immigrants, heritage speakers, and L2 speakers. Lingua 292 ► pp. 103573 ff.
Petersen, Jan Heegård, Gert Foget Hansen, Jacob Thøgersen & Karoline Kühl
2021. Linguistic Proficiency: A Quantitative Approach to Immigrant and Heritage Speakers of Danish
. Corpus Linguistics and Linguistic Theory 17:2 ► pp. 465 ff.
Puig-Mayenco, Eloi, Ian Cunnings, Fatih Bayram, David Miller, Susagna Tubau & Jason Rothman
2018. Language Dominance Affects Bilingual Performance and Processing Outcomes in Adulthood. Frontiers in Psychology 9
Putnam, Michael T., Lara Schwarz & Andrew D. Hoffman
2021. Morphology of Heritage Languages. In The Cambridge Handbook of Heritage Languages and Linguistics, ► pp. 613 ff.
Sippola, Eeva
2022. Spanish contact influence in a Finnish heritage community in Misiones, Argentina. Nordic Journal of Linguistics 45:3 ► pp. 348 ff.
Sopata, Aldona & Kamil Długosz
2022. The effects of language input on word order in German as a heritage and majority language. Language Acquisition 29:2 ► pp. 198 ff.
Thane, Patrick, Michele Goldin, Abril Jimenez, Esther Hur, Julio Cesar Lopez Otero & Jennifer Austin
2022. Where we are and where we ought to be: The need for research-based assessments for dual language immersion learners. NABE Journal of Research and Practice 12:2 ► pp. 84 ff.
Uygun, Serkan & Harald Clahsen
2021. Morphological processing in heritage speakers: A masked priming study on the Turkish aorist. Bilingualism: Language and Cognition 24:3 ► pp. 415 ff.
This list is based on CrossRef data as of 18 november 2023. 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.