APA (7e ed.) Bronvermelding
O'Brien Derek. (2004). Gk with derek the ultimate general knowledge and quiz compendium: 3 science and wildlife. Penguin Books.
Chicago (17e ed.) Bronvermelding
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 3 Science and Wildlife. New Delhi: Penguin Books, 2004.
MLA (9e ed.) Bronvermelding
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 3 Science and Wildlife. Penguin Books, 2004.
Let op: Deze citaties zijn niet altijd 100% accuraat.