Schuh, R. T., & Brower, A. V. Z. (2009). Biological systematics: Principles and applications (2nd ed.). Comstock Pub. Associates/Cornell University Press.

Schuh, Randall T., and Andrew V. Z. Brower. Biological Systematics: Principles and Applications. 2nd ed. Ithaca: Comstock Pub. Associates/Cornell University Press, 2009.

Schuh, Randall T., and Andrew V. Z. Brower. Biological Systematics: Principles and Applications. 2nd ed. Comstock Pub. Associates/Cornell University Press, 2009.