APA-referens (7:e uppl.)

Ritter, C. (1968). The essence of Plato's philosophy. Russell & Russell.

Chicago-referens (17:e uppl.)

Ritter, Constantin. The Essence of Plato's Philosophy. New York: Russell & Russell, 1968.

MLA-referens (9:e uppl.)

Ritter, Constantin. The Essence of Plato's Philosophy. Russell & Russell, 1968.