Benson, S., & Nagel, R. E. s. Endangered species.
Cita Chicago (17th ed.)Benson, Sonia, i Rob. Endangered species Nagel. Endangered Species.
Cita MLA (9th ed.)Benson, Sonia, i Rob. Endangered species Nagel. Endangered Species.
Atenció: Aquestes cites poden no estar 100% correctes.