Armour, R. (1962). It all started with Columbus. Cox & Wyman Ltd.
Chicago Style aipamenaArmour, Richard. It All Started with Columbus. London: Cox & Wyman Ltd, 1962.
MLA aipamenaArmour, Richard. It All Started with Columbus. Cox & Wyman Ltd, 1962.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.