Παραπομπή APA

Gardner, M. (1997). Penrose tiles to trapdoor ciphers: --and the return of Dr. Matrix (Rev. ed.). Mathematical Association of America.

Παραπομπή Chicago Style

Gardner, Martin. Penrose Tiles to Trapdoor Ciphers: --and the Return of Dr. Matrix. Rev. ed. Washington, D.C.: Mathematical Association of America, 1997.

Παραπομπή MLA

Gardner, Martin. Penrose Tiles to Trapdoor Ciphers: --and the Return of Dr. Matrix. Rev. ed. Mathematical Association of America, 1997.