Yeo, A. (2007). Trig or treat: An encyclopedia of trigonometric identity proofs (TIPs), intellectually challenging games. World Scientific Pub..
Lua i Stíl Chicago (17ú heag.)Yeo, Adrian. Trig or Treat: An Encyclopedia of Trigonometric Identity Proofs (TIPs), Intellectually Challenging Games. Singapore: World Scientific Pub., 2007.
Lua MLA (9ú heag.)Yeo, Adrian. Trig or Treat: An Encyclopedia of Trigonometric Identity Proofs (TIPs), Intellectually Challenging Games. World Scientific Pub., 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.