00573nam a2200169Ia 4500008004100000020001800041022001300059040001300072082001500085100002000100245008700120250001200207260006300219300004200282500005000324650002900374191130s1997##################000#0#eng##  a9780883855218  a97070505  aACLcACL  a793.73 GAR  aGardner, Martin  aPenrose tiles to trapdoor ciphers : --and the return of Dr. MatrixcMartin Gardner  aRev. ed  aWsshington, DCbMathematical Association of Americacc1997  aix, 319 p. : ill. (some col.) ; 24 cm  aIncludes bibliographical references and index  aMathematical recreations