Dyfyniad APA

Leedy, P. D., & Ormrod, J. E. (2005). Practical research: Planning and design (8th ed.). Prentice Hall.

Dyfyniad Arddull Chicago

Leedy, Paul D., and Jeanne Ellis Ormrod. Practical Research: Planning and Design. 8th ed. Upper Saddle River, N.J.: Prentice Hall, 2005.

Dyfyniad MLA

Leedy, Paul D., and Jeanne Ellis Ormrod. Practical Research: Planning and Design. 8th ed. Prentice Hall, 2005.

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