Cita APA (7a ed.)

Christofferson, H. C. (1933). Geometry Professionalized for Teachers. Columbia University.

Cita Chicago Style (17a ed.)

Christofferson, Halbert Carl. Geometry Professionalized for Teachers. New York: Columbia University, 1933.

Cita MLA (8a ed.)

Christofferson, Halbert Carl. Geometry Professionalized for Teachers. Columbia University, 1933.