APA (7th ed.) Citation

Endler, J. A. (1977). Geographic variation, speciation, and clines. Princeton University Press.

Chicago Style (17th ed.) Citation

Endler, John A. Geographic Variation, Speciation, and Clines. Princeton, N.J: Princeton University Press, 1977.

MLA (9th ed.) Citation

Endler, John A. Geographic Variation, Speciation, and Clines. Princeton University Press, 1977.