Cita APA (7th ed.)
Ritchie, D. D., & Carola, R. (1983). Biology. Addison-Wesley Publishing Co..
Cita Chicago (17th ed.)
Ritchie, Donald D., i Robert Carola. Biology. California: Addison-Wesley Publishing Co., 1983.
Cita MLA (9th ed.)
Ritchie, Donald D., i Robert Carola. Biology. Addison-Wesley Publishing Co., 1983.
Atenció: Aquestes cites poden no estar 100% correctes.