00697nam a2200217Ia 4500 191130s1997##################000#0#eng## 9780883855218 97070505 ACL ACL 793.73 GAR Gardner, Martin Penrose tiles to trapdoor ciphers : --and the return of Dr. Matrix Martin Gardner Rev. ed Wsshington, DC Mathematical Association of America c1997 ix, 319 p. : ill. (some col.) ; 24 cm Includes bibliographical references and index Mathematical recreations a69183c8ac10000c686ea90c3e47b4c9 341476 33513 33513 0 0 0 0 ACL ACL 6B 2020-10-09 0 793.73 GAR 103072 2020-10-09 00:00:00 2020-10-09 BK