Watt, D. (1967). History of the World in the Twentieth Century. Pan Books.
Dyfyniad Arddull ChicagoWatt, D.C. History of the World in the Twentieth Century. London: Pan Books, 1967.
Dyfyniad MLAWatt, D.C. History of the World in the Twentieth Century. Pan Books, 1967.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.