Cita APA (7th ed.)
O'Brien Derek. (2004). Gk with Derek the ultimate general knowledge and quiz compendium: 1 history and geography. Penguin Books.
Cita Chicago (17th ed.)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. New Delhi: Penguin Books, 2004.
Cita MLA (9th ed.)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. Penguin Books, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.