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Dyfyniad Arddull ChicagoWorld Book, Inc. The World Book Encyclopedia: Q-r. Chicago: World Book, 1996.
Dyfyniad MLAWorld Book, Inc. The World Book Encyclopedia: Q-r. World Book, 1996.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.