Cita APA (7th ed.)

Robbins, E. R. (1937). Plane trigonometry. American Book Company.

Cita Chicago (17th ed.)

Robbins, Edward R. Plane Trigonometry. Nueva York: American Book Company, 1937.

Cita MLA (9th ed.)

Robbins, Edward R. Plane Trigonometry. American Book Company, 1937.