Gaya APA

Babbie, E, R., Wagenaar, T, C. (1986). The practice of social research (4th edition). Belmont: Wadsworth Pub. Co..

Gaya MLA

Babbie, Earl, R.., Wagenaar, Theodore, C.. "The practice of social research". 4th edition Belmont: Wadsworth Pub. Co., 1986. Text.