APA (7th ed.) Citation

Ringenberg, L. A. (1967). Informal geometry. John Wiley and Sons.

Chicago Style (17th ed.) Citation

Ringenberg, Lawrence A. Informal Geometry. New York: John Wiley and Sons, 1967.

MLA (9th ed.) Citation

Ringenberg, Lawrence A. Informal Geometry. John Wiley and Sons, 1967.