Gaya APA

Sayre, A, P. (2002). Secrets of sound : studying the calls and songs of whales, elephants and birds . Boston: Houghton Mifflin Company.

Gaya MLA

Sayre, April, Pulley. "Secrets of sound : studying the calls and songs of whales, elephants and birds". Boston: Houghton Mifflin Company, 2002. Text.