1. Allard, R. W. 1965. Genetic systems associated with colonizing ability in predominantly self-pollinated species. In Baker, H. G., and Stebbins, G. L. eds. The Genetics of Colonizing Species, pp. 49–76.
2. Alston Ralph E. 1967. Biochemical systematics. In Dobzhansky, Th., Hecht, M. K., and Steere, W. C., eds. Evolutionary Biology. New York, Appleton-Century-Crofts. pp. 197–305.
3. Alston Ralph E. and B. L. Turner. 1963. Biochemical Systematics. Englewood Cliffs, N. J. Prentice-Hall, Inc. 404 pp.
4. Anderson, E., and G. L. Stebbins. 1954. Hybridization as an evolutionary stimulus. Evolution, 8:378–388.
5. Avery, A. G., S. Satina, and J. Rietsema. 1959. Blakeslee: The Genus Datura. New York, The Ronald Press Company. 329 pp.