Cita APA (7a ed.)

Derlega, V. J., & Grzelak, J. (1982). Cooperation and helping behavior: Theories and research. Acad. Pr.

Cita Chicago Style (17a ed.)

Derlega, Valerian J., y Janusz Grzelak. Cooperation and Helping Behavior: Theories and Research. New York [u.a.]: Acad. Pr, 1982.

Cita MLA (8a ed.)

Derlega, Valerian J., y Janusz Grzelak. Cooperation and Helping Behavior: Theories and Research. Acad. Pr, 1982.