Zimmermann, W., & Cunningham, S. (1991). Visualization in teaching and learning mathematics. The Mathematical Association of America.
Lua i Stíl Chicago (17ú heag.)Zimmermann, Walter, agus Steve Cunningham. Visualization in Teaching and Learning Mathematics. Washington, D.C: The Mathematical Association of America, 1991.
Lua MLA (9ú heag.)Zimmermann, Walter, agus Steve Cunningham. Visualization in Teaching and Learning Mathematics. The Mathematical Association of America, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.