Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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