"The Origins of Indo-European Languages," by Colin Renfrew; SCIENTIFIC AMERlCAN, October, 1989.

Allen, W. Sidney Sandhi

Allman, William F. "The Mother Tongue." U.S. News and World Report 5 (November 1990)

American Indian and Indoeuropean Studies Papers in Honor of Madison S. Beeler; Ed. by Klar, Kathryn / Langdon, Margaret / Silver, Shirley.

Arlotto, Anthony, Introduction to Historical Linguistics (New York 1971).

Beekes, Robert S.P. Comparative Indo-European Linguistics: an introduction. Amsterdam/Philadelphia: John Benjamins, 1995

Benveniste, Emile, Indo-European Language and Society (London 1973).

Bomhard, Allan R. / Kerns, John C. The Nostratic Macrofamily. A Study in Distant Linguistic Relationship

Bomhard, Allan R. 1984. Toward Proto-Nostratic: A New Approach to the Comparison of Proto-Indo-European and Proto-Afroasiatic. Amsterdam/Philadelphia: John Benjamins Publishing Company

Bomhard, Allan R. 1992. "The Nostratic Macrofamily (with special reference to Indo-European)" Word 43: 61-83.

Bopp, F. 1833, Comparative Grammar of Sanskrit , Zend , Greek , Latin and Lithuanian, Old Slavic, Gothic and German.

Brugmann, Karl Kurze vergleichende Grammatik der indogermanischen Sprachen

Brugmann, Karl. 1888. A Comparative Grammar of the Indo-Germanic Languages. 5 vol. 2nd reprint 1972. Varanasi, India: Chowkhamba Sanskrit Series Office

Buck, Carl D., A Dictionary of Selected Synonyms in the Principal Indo-European Languages (Chicago 1949).

Burgmann, Karl Outline of Comparative Indo-European Grammar, 1897-1916.

Cavalli-Sforza, Luigi Luca and Cavalli-Sforza, Francesco. 1995. The Great Human Diasporas: The History of Diversity and Evolution. New York etal. Helix Books. Addison-Wesley Publishing Company

Childe, V. Gordon. 1926. The Aryans: A Study of Indo-European Origins. 2nd reprint 1987. New York: Dorset Press

Colarusso, John. 1994. Phyletic Links between Proto-Indo-European and Proto-Northwest Caucasian. Mother Tongue 21. January 1994.

Collinge, N. E., The Laws of Indo-European (Amsterdam 1985).

Desnitskaya A.V., The matter of studying relations of Indo-European languages, Moscow, 1955.

Devoto, G., Origini Indoeuropee, Firenze, 1962.

Ehret, Christopher. 1995. Reconstructing Proto-Afroasiatic (Proto-Afrasian): Vowels, Tone, Consonants, and Vocabulary. University of California Publications in Linguistics: Vol. 126. Berkeley and Los Angeles. University of California Press

Gamkrelidze, Thomas V. / Ivanov, Vjacheslav V. The Indo-European language and the Indo-Europeans

Gould, Stephen J. "Grimm's Greatest Tale." Natural History (February 1989):

Griffen, Toby B. "Nostratic and Germano-European." General Linguistics 29, iii (1989): 139-49.

Hencken, H., Indo-European Languages and Archaeology, Menasha, 1955.

Hirt, H., Indogermanische Grammatik, Hdlb, 1921-1937.

Historical, Indo-European, and Lexicographical Studies A Festschrift for Ladislav Zgusta on the Occasion of his 70th Birthday

Indo-European Numerals Ed. by Gvozdanovic, Jadranka.  Mouton de Gruyter. 1992.

Indogermanica et Caucasica Festschrift für Karl Horst Schmidt zum 65. Geburtstag.  Hrsg. v. Bielmeier, Roland / Stempel, Reinhard. 1994.

Ivanov, Viacheslav, Common Indo-European, Common Slavic and Anatolian Language Systems, Moscow, 1965.

John  Kerns. 1994. The Nostratic Macrofamily A Study in Distant Linguistic Relationship. Trends in Linguistics: Studies and Monographs 74. Berlin, New York City: Mouton de Gruyter
1996. Indo-European and the Nostratic Hypothesis. Studia Nostratica, 1. Charleston, S. C.: Signum Desktop Publishing

Kaiser, M. and Shevoroshkin, V., "Nostratic." Annual Review of Anthropology 17 (1988): 302-29.

Kaiser, M., and Shevoroshkin V., "On Recent Comparisons between Language Families: The Case of Indo-European and Afro-Asiatic." General Linguistics 27, i (1987): 34-36.

Keiler, Allan R. A Phonological Study of the Indo-European Laryngeals  Mouton de Gruyter. 1970.

Klimov, Georgij A. 1977. Tipologija Jazykov Aktivnogo Stroja. Moscow: Nauka; 1983. Printsipy Kontensivnoi Tipologij. Moscow: Nauka

Krahe, Hans Indogermanische Sprachwissenschaft. Teil I: Einleitung und Lautlehre. Teil II: Formenlehre 1969.

Kurilowich, J., The Inflectional Cetegories of Indo-European, Hdlb., 1964.

Kurylowicz, Jerzy, A new Indo-European Grammar,   1968.

Lehmann, W., Proto-Indo-European Syntax, Austin, 1974.

Levin, Saul. The Indo-European and Semitic Languages. Albany: SUNY Albany Press, 1971.

Lindeman, Fredrik O. Einführung in die Laryngaltheorie. Mit Beitr. v. Borgstrom, Carl H. 1970.

Meillet, Antoine, Introduction to Comparative Studies of Indo-European Languages.

Meillet, Antoine, The Comparative Method in Historical Linguistics (Paris 1967).

Meillet, Antoine (trans. S. N. Rosenberg), The Indo-European Dialects (Huntsville 1967).

Moscati, Sabatino, et alii. 1969. An Introduction to the Comparative Grammar of the Semitic Languages: Phonology and Morphology. Wiesbaden: Otto Harassowitz

Nussbaum, Alan J. Head and Horn in Indo-European 1985.

Pedersen, Holgar, The Discovery of Language (Bloomington 1959).

Pokorny, Julius, Indogermanisches etymologisches Woertenbuch, Bern - Munchen, 1950-1969.

Pokorny, Julius, 1959. Indogermanisches Etymologisches Wörterbuch. Volume I. Bern and Munich: Francke Verlag

Rask, Ramos, 1818, "Investigation on the origin of the Old Norse or Icelandic Language"

Sandhi Phenomena in the Languages of Europe Ed. by Andersen, Henning. Mouton de Gruyter. 1986.

Savchenko, A. N., The Comparative Grammar of Indo-European Languages, Moscow, 1974.

Schmid, Wolfgang P. Linguisticae Scientiae Collectanea. Ausgewählte Schriften anläßlich seines 65. Geburtstag 1994.

Schulte, Michael Grundfragen der Umlautphonemisierung 1998.

Shevoroshkin, V.V. "The Mother Tongue." The Sciences (Spring 1990?).

Sihler, Andrew L. New Comparative Grammar of Greek and Latin. New York and Oxford: Oxford University Press, 1995.

Sihler, Andrew, New Comparative Grammar of Greek and Latin (New York 1995).

Studies in Memory of Warren Cowgill (1929-1985) Papers from the Fourth East Coast Indo-European Conference Cornell University, June 6-9, 1985.  Ed. by Watkins, Calvert. 1987.

Szemerenyi, Oswald, Comparative-historical linguistics : Indo-European and Finno-Ugric (Amsterdam 1993).

Szemerenyi, Oswald, Introduction to Comparative Linguistics.

The New Sound of Indo-European, Essays in Phonological Reconstruction. Ed. by Vennemann, Theo. Mouton de Gruyter. 1989.

Watkins, C., Indogermanische Grammatik, Hdlb., 1964.

Watkins, Calvert (ed.), The American Heritage Dictionary of Indo-European Roots (Boston 1985).

Winter, Werner (ed.), Evidence for Laryngals (The Hague 1965).

Wright, Robert. "Quest for the Mother Tongue." Atlantic 267.4 (April 1991)