Παραπομπή APA

Beer, G. D. (1960). Vertebrate zoology. Sidgwick and jackson ltd.

Παραπομπή Chicago Style

Beer, Gavin De. Vertebrate Zoology. London: Sidgwick and jackson ltd, 1960.

Παραπομπή MLA

Beer, Gavin De. Vertebrate Zoology. Sidgwick and jackson ltd, 1960.