APA

Babbie E. R., . (2001). The practice of social research. Belmont, CA: Wadsworth Thomson Learning.

Chicago

Babbie Earl R, . 2001. The practice of social research. Belmont, CA: Wadsworth Thomson Learning.

Harvard

Babbie E. R., . (2001). The practice of social research. Belmont, CA: Wadsworth Thomson Learning.

MLA

Babbie Earl R, . The practice of social research. Belmont, CA: Wadsworth Thomson Learning. 2001.