Cita APA (7a ed.)

Lankford, F. G. J., & Clark, J. R. (1961). Essential mathematics. Harcourt Brace and World.

Cita Chicago Style (17a ed.)

Lankford, Francis G. Jr, y J. R. Clark. Essential Mathematics. New York: Harcourt Brace and World, 1961.

Cita MLA (9a ed.)

Lankford, Francis G. Jr, y J. R. Clark. Essential Mathematics. Harcourt Brace and World, 1961.