APA-referens (7:e uppl.)
O'Brien Derek. (2004). Gk with derek the ultimate general knowledge and quiz compendium: 3 science and wildlife. Penguin Books.
Chicago-referens (17:e uppl.)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 3 Science and Wildlife. New Delhi: Penguin Books, 2004.
MLA-referens (9:e uppl.)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 3 Science and Wildlife. Penguin Books, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.