Clawson, C. (2004). Mathemtical mysteries. Viva.
Lua i Stíl Chicago (17ú heag.)Clawson, Calvin. Mathemtical Mysteries. New Delhi: Viva, 2004.
Lua MLA (9ú heag.)Clawson, Calvin. Mathemtical Mysteries. Viva, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.