Cita APA (7a ed.)

Ross, E. A. (1920). Principles of sociology. The Century Co.

Cita Chicago Style (17a ed.)

Ross, Edward Alsworth. Principles of Sociology. New York: The Century Co, 1920.

Cita MLA (9a ed.)

Ross, Edward Alsworth. Principles of Sociology. The Century Co, 1920.