TY  - BOOK
AU  - Martin , Gardner
TI  - Penrose tiles to trapdoor ciphers
SN  - 76101986
U1  - 793.74 MAR 
PY  - 1989///
CY  - New York
PB  - W. H. Freeman
KW  - Humanities & Natural Science
KW  - Arts and Recreation
N1  - NA
ER  -