Nelsen, R. B. (1993). Proofs without words: Exercises in visual thinking. The Mathematical Association of America.
Citazione stile Chigago Style (17a edizione)Nelsen, Roger B. Proofs Without Words: Exercises in Visual Thinking. Washington, D.C: The Mathematical Association of America, 1993.
Citatione MLA (9a ed.)Nelsen, Roger B. Proofs Without Words: Exercises in Visual Thinking. The Mathematical Association of America, 1993.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.