Gaya APA

Leedy, P, D., Ormrod, J, E. (2005). Practical Research: Planing and Design (8th. Ed). Upper Saddle River, NJ: Pearson.

Gaya MLA

Leedy, Paul, D., Ormrod, Jeanne, Ellis. "Practical Research: Planing and Design". 8th. Ed Upper Saddle River, NJ: Pearson, 2005. Text.