Byrd (2015:10) Byrd, Andrew Miles (2015), "The Phonology of Proto-Indo-European"(PDF), in Klein, Jared S.; Joseph, Brian; Fritz, Matthias (eds.), Comparative Indo-European Linguistics. An International Handbook of Language Comparison and the Reconstruction of Indo-European, Berlin: Mouton de Gruyter
Garrett (1998:16) Garrett, Andrew (1998), "Adjarian's Law, the glottalic theory, and the position of Armenian"(PDF), in Bergen, Benjamin K.; Plauché, Madelaine C.; Bailey, Ashlee C. (eds.), Proceedings of the Twenty-Fourth Annual Meeting of the Berkeley Linguistics Society, February 14-16,1998: Special Session on Indo-European Subgrouping and Internal Relations, Berkeley: Berkeley Linguistics Society, pp. 12–23
Garrett (1998:20) Garrett, Andrew (1998), "Adjarian's Law, the glottalic theory, and the position of Armenian"(PDF), in Bergen, Benjamin K.; Plauché, Madelaine C.; Bailey, Ashlee C. (eds.), Proceedings of the Twenty-Fourth Annual Meeting of the Berkeley Linguistics Society, February 14-16,1998: Special Session on Indo-European Subgrouping and Internal Relations, Berkeley: Berkeley Linguistics Society, pp. 12–23
Frederik Kortlandt, 'Glottalic Consonants in Sindhi and Proto-Indo-European', reprinted in Studies in Germanic, Indo-European, and Indo-Uralic, Amsterdam: Rodopi (2010), pp. 121-124. Counterarguments exist for his argument of no discernible substrate influence on the development of the specific Sindhi glottalization.[clarification needed] See also Michael Witzel, "Substrate Languages in Old Indo-Aryan", Electronic Journal of Vedic Studies 1999 (http://www.ejvs.laurasianacademy.com/ejvs0501/0501ART.PDFArchived 2013-09-21 at the Wayback Machine).
Frederik Kortlandt, 'Glottalic Consonants in Sindhi and Proto-Indo-European', reprinted in Studies in Germanic, Indo-European, and Indo-Uralic, Amsterdam: Rodopi (2010), pp. 121-124. Counterarguments exist for his argument of no discernible substrate influence on the development of the specific Sindhi glottalization.[clarification needed] See also Michael Witzel, "Substrate Languages in Old Indo-Aryan", Electronic Journal of Vedic Studies 1999 (http://www.ejvs.laurasianacademy.com/ejvs0501/0501ART.PDFArchived 2013-09-21 at the Wayback Machine).
