Παραπομπή APA

Etkin, W., & Gilbert, L. I. (1968). Metamorphosis: A problem in developmental biology. Appleton-Century-Crofts.

Παραπομπή Chicago Style

Etkin, William, και Lawrence I. Gilbert. Metamorphosis: A Problem in Developmental Biology. New York: Appleton-Century-Crofts, 1968.

Παραπομπή MLA

Etkin, William, και Lawrence I. Gilbert. Metamorphosis: A Problem in Developmental Biology. Appleton-Century-Crofts, 1968.