APA

Schaefer، Richard, . (2005). Sociology. : Higher Eduacation،.

Chicago

Schaefer، Richard, . 2005. Sociology. : Higher Eduacation،.

Harvard

Schaefer، Richard, . (2005). Sociology. : Higher Eduacation،.

MLA

Schaefer، Richard, . Sociology. : Higher Eduacation،. 2005.