APA

Perls F. S., . (1969). Ego, hunger, and aggression: the beginning of gestalt therapy. New York: Random House.

Chicago

Perls Frederick S, . 1969. Ego, hunger, and aggression: the beginning of gestalt therapy. New York: Random House.

Harvard

Perls F. S., . (1969). Ego, hunger, and aggression: the beginning of gestalt therapy. New York: Random House.

MLA

Perls Frederick S, . Ego, hunger, and aggression: the beginning of gestalt therapy. New York: Random House. 1969.