Cita APA (7th ed.)

Nelsen, R. B. (1993). Proofs without words: Exercises in visual thinking. The Mathematical Association of America.

Cita Chicago (17th ed.)

Nelsen, Roger B. Proofs Without Words: Exercises in Visual Thinking. Washington, D.C: The Mathematical Association of America, 1993.

Cita MLA (9th ed.)

Nelsen, Roger B. Proofs Without Words: Exercises in Visual Thinking. The Mathematical Association of America, 1993.