Cita APA (7th ed.)

Krogh, D. (2002). Biology: A guide to the natural world (2nd ediotion.). Prentice Hall.

Cita Chicago (17th ed.)

Krogh, David. Biology: A Guide to the Natural World. 2nd ediotion. Upper Saddle River, N.J: Prentice Hall, 2002.

Cita MLA (9th ed.)

Krogh, David. Biology: A Guide to the Natural World. 2nd ediotion. Prentice Hall, 2002.