Dyfyniad APA

Grava, S. (2003). Urban transportation systems. New York: McGraw-Hill.

Dyfyniad Arddull Chicago

Grava, Sigurd. Urban Transportation Systems. New York: McGraw-Hill, 2003.

Dyfyniad MLA

Grava, Sigurd. Urban Transportation Systems. New York: McGraw-Hill, 2003.

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