Dyfyniad APA

(1979). World Almanac & Book of Facts 1979. News Paper Enterprise association.

Dyfyniad Arddull Chicago

World Almanac & Book of Facts 1979. New York: News Paper Enterprise association, 1979.

Dyfyniad MLA

World Almanac & Book of Facts 1979. News Paper Enterprise association, 1979.

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