APA

Koestenbaum P., . (1968). Philosophy, a general introduction. [New York]: American Book Co.

Chicago

Koestenbaum Peter, . 1968. Philosophy, a general introduction. [New York]: American Book Co.

Harvard

Koestenbaum P., . (1968). Philosophy, a general introduction. [New York]: American Book Co.

MLA

Koestenbaum Peter, . Philosophy, a general introduction. [New York]: American Book Co. 1968.