Cita APA

(1991). The official world wildlife fund guide to endagered species of Norh America. Washington, D.C.: Walton Beacham.

Citación estilo Chicago

The Official World Wildlife Fund Guide to Endagered Species of Norh America. Washington, D.C.: Walton Beacham, 1991.

Cita MLA

The Official World Wildlife Fund Guide to Endagered Species of Norh America. Washington, D.C.: Walton Beacham, 1991.

Precaución: Estas citas no son 100% exactas.