Dyfyniad APA

Dewey, M. (1989). Dewey decimal classification and relative index (20th ed.). Forest Press.

Dyfyniad Arddull Chicago

Dewey, Melvil. Dewey Decimal Classification and Relative Index. 20th ed. Albany, New York: Forest Press, 1989.

Dyfyniad MLA

Dewey, Melvil. Dewey Decimal Classification and Relative Index. 20th ed. Forest Press, 1989.

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