Cita APA (7th ed.)

Schefler, W. C. (1976). Biology: Principles and issues. Addison - Wesley.

Cita Chicago (17th ed.)

Schefler, William C. Biology: Principles and Issues. Reading Mass: Addison - Wesley, 1976.

Cita MLA (9th ed.)

Schefler, William C. Biology: Principles and Issues. Addison - Wesley, 1976.