Columbia subject headings:
Altruism.
Altruistic behavior in animals.
Freud, Sigmund, 1856-1939.
Harvard subject headings:
Altruism
Altruistic behavior in animals
Freud, Sigmund, 1856-1939--Views on altruism.
Princeton subject headings:
Altruism.
Altruistic behavior in animals.
Freud, Sigmund, 1856-1939.