Dyfyniad APA

World Book, I. (2011). The World Book encyclopedia. Chicago: World Book.

Dyfyniad Arddull Chicago

World Book, Inc. The World Book Encyclopedia. Chicago: World Book, 2011.

Dyfyniad MLA

World Book, Inc. The World Book Encyclopedia. Chicago: World Book, 2011.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.