Cita APA (7th ed.)

Gottfried & Sandra S. (1993). Biology Today. Mosby-Year Book.

Cita Chicago (17th ed.)

Gottfried i Sandra S. Biology Today. St. Louis, MO: Mosby-Year Book, 1993.

Cita MLA (9th ed.)

Gottfried i Sandra S. Biology Today. Mosby-Year Book, 1993.