REFERENCES
- Berggren, W.A., and John A. Van Couvering, eds. 1984. Catastrophes and earth history. Princeton: Princeton University Press.
- Bomhard, Allan R. n.d. (1990). A sample of the comparative vocabulary of the Nostratic languages, revised. Boston.
- Clube, Victor, and Bill Napier. 1982. The cosmic serpent: A catastrophist view of earth history. New York: Universe Books.
- Mann, Stuart E. 1984–87. An Indo-European comparative dictionary. Hamburg: Buske.
- Pokorny, Julius. 1959. Indogermanisches etymologisches Wörterbuch. 2 vols. Bern and Munich: Francke.
- Schwartz, Benjamin. 1947. The root and its modification in primitive Indo-European. Doctoral dissertation. New York: Columbia University.
- Swadesh, Morris. 1960. Tras la huella de la prehistoria. Suplementos científicos, 2da serie, num. 26. Mexico City: Universidad Nacional.
- Trager, George L. 1955. “Language.” Encyclopaedia Britannica 13: 696–703. Chicago.
- Trager, George L..1972. Language. San Francisco: Chandler.
- Watkins, Calvert. 1985. The American heritage dictionary of Indo-European roots, revised. Boston: Houghton Mifflin.
- Wescott, Roger W. 1974. “Types of apophony in proto-speech.” Language origins. ed. Roger W. Wescott. Silver Spring, MD: Linstok. pp. 125–76.
- Wescott, Roger W. 1975. “Allolinguistics: Exploring the peripheries of speech.” The Second LACUS Forum. Ed. Peter A. Reich. pp. 497–513. Columbia, SC: Hornbeam Press.
- Wescott, Roger W. 1978. “Polymathics and catastrophism: A multidisciplinary approach to problems of evolutionary theory.” Kronos 4:3–20.
- Wescott, Roger W. 1988. “Derogatory use of the marginal phoneme /b/ in Proto-Indo-European.” Journal of Indo-European studies 16: 365–68.