Dyfyniad APA
O'Brien Derek. (2004). Gk with Derek the ultimate general knowledge and quiz compendium: 1 history and geography. Penguin Books.
Dyfyniad Arddull Chicago
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. New Delhi: Penguin Books, 2004.
Dyfyniad MLA
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. Penguin Books, 2004.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.