Gaya APA

Leedy, P, D., Ormrod, J, E. (2010). Practical Research : Planning And Design (9th.ed.). Upper Saddle River, New Jersey: Pearson Education.

Gaya MLA

Leedy, Paul, D.., Ormrod, Jeanne, E.. "Practical Research : Planning And Design". 9th.ed. Upper Saddle River, New Jersey: Pearson Education, 2010. Teks.