Dyfyniad APA

Leedy, P. D. (1980). Practical research: Planning and Desgn (2nd ed.). Macmillan.

Dyfyniad Arddull Chicago

Leedy, Paul D. Practical Research: Planning and Desgn. 2nd ed. New York: Macmillan, 1980.

Dyfyniad MLA

Leedy, Paul D. Practical Research: Planning and Desgn. 2nd ed. Macmillan, 1980.

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