Cita APA (7a ed.)

Frings, H., & Frings, M. (1970). Concepts of Zoology. The Macmillan Company.

Cita Chicago Style (17a ed.)

Frings, Hubert, y Mable Frings. Concepts of Zoology. [S.l.]: The Macmillan Company, 1970.

Cita MLA (9a ed.)

Frings, Hubert, y Mable Frings. Concepts of Zoology. The Macmillan Company, 1970.