Armour, R. (1962). It all started with Columbus. Cox & Wyman Ltd.
Dyfyniad Arddull ChicagoArmour, Richard. It All Started with Columbus. London: Cox & Wyman Ltd, 1962.
Dyfyniad MLAArmour, Richard. It All Started with Columbus. Cox & Wyman Ltd, 1962.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.