Dyfyniad APA

International, W. B. -. C. (1980). Science Year: The world book science annual. U.S.A.

Dyfyniad Arddull Chicago

International, World Book - Childcraft. Science Year: The World Book Science Annual. Chicago: U.S.A, 1980.

Dyfyniad MLA

International, World Book - Childcraft. Science Year: The World Book Science Annual. U.S.A, 1980.

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