Cita APA (7a ed.)
Samuelson, P. A. (1993). Altruism as a problem involving group versus individual selection in economics and biology. American Economic Review, 83, 143-149.
Cita Chicago Style (17a ed.)
Samuelson, Paul Anthony. "Altruism as a Problem Involving Group Versus Individual Selection in Economics and Biology." American Economic Review 83 (1993): 143-149.
Cita MLA (9a ed.)
Samuelson, Paul Anthony. "Altruism as a Problem Involving Group Versus Individual Selection in Economics and Biology." American Economic Review, vol. 83, 1993, pp. 143-149.
Precaución: Estas citas no son 100% exactas.