Citazione Stile APA (7a Edizione)
O'Brien Derek. (2004). Gk with Derek the ultimate general knowledge and quiz compendium: 1 history and geography. Penguin Books.
Citazione stile Chigago Style (17a edizione)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. New Delhi: Penguin Books, 2004.
Citatione MLA (9a ed.)
O'Brien Derek. Gk with Derek the Ultimate General Knowledge and Quiz Compendium: 1 History and Geography. Penguin Books, 2004.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.