Dyfyniad APA

(1973). Statistical Abstract of the United State 1973. Department of Commerce.

Dyfyniad Arddull Chicago

Statistical Abstract of the United State 1973. Washington, D.C: Department of Commerce, 1973.

Dyfyniad MLA

Statistical Abstract of the United State 1973. Department of Commerce, 1973.

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