Παραπομπή APA

Orr, R. T. (1976). Vertebrate biology (4th ed.). Saunders.

Παραπομπή Chicago Style

Orr, Robert T. Vertebrate Biology. 4th ed. Philadelphia: Saunders, 1976.

Παραπομπή MLA

Orr, Robert T. Vertebrate Biology. 4th ed. Saunders, 1976.