APA-referens (7:e uppl.)

Levi, H. (1960). Foundations of geometry and trignometry. Prentice Hall.

Chicago-referens (17:e uppl.)

Levi, Howard. Foundations of Geometry and Trignometry. Englewood Cliffs: Prentice Hall, 1960.

MLA-referens (9:e uppl.)

Levi, Howard. Foundations of Geometry and Trignometry. Prentice Hall, 1960.