APA (7th ed.) Citation

Montada, L., Bierhoff, H., & Bierhoff, H. (1991). Altruism in social systems. Hogrefe.

Chicago Style (17th ed.) Citation

Montada, Leo, Hans-Werner Bierhoff, and Hans-Werner Bierhoff. Altruism in Social Systems. Lewiston, NY Stuttgart [u.a.]: Hogrefe, 1991.

MLA (8th ed.) Citation

Montada, Leo, et al. Altruism in Social Systems. Hogrefe, 1991.