Gardner, M. (1987). Riddles of the sphinx and other mathematical puzzle tales. Mathematical Association of America.
Dyfyniad Arddull ChicagoGardner, Martin. Riddles of the Sphinx and Other Mathematical Puzzle Tales. Washington, D.C.: Mathematical Association of America, 1987.
Dyfyniad MLAGardner, Martin. Riddles of the Sphinx and Other Mathematical Puzzle Tales. Mathematical Association of America, 1987.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.