Dyfyniad APA

(1969). U.S book of facts statistics and information. Essendess.

Dyfyniad Arddull Chicago

U.S Book of Facts Statistics and Information. New York: Essendess, 1969.

Dyfyniad MLA

U.S Book of Facts Statistics and Information. Essendess, 1969.

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