Gardner, M. (1987). Riddles of the sphinx and other mathematical puzzle tales. Mathematical Association of America.
Lua i Stíl Chicago (17ú heag.)Gardner, Martin. Riddles of the Sphinx and Other Mathematical Puzzle Tales. Washington, D.C.: Mathematical Association of America, 1987.
Lua MLA (9ú heag.)Gardner, Martin. Riddles of the Sphinx and Other Mathematical Puzzle Tales. Mathematical Association of America, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.