TY  - BOOK
AU  - Gardner,Martin
TI  - Knotted doughnuts and other mathematical entertainments
SN  - 0716717999 (pbk.)
U1  - 793.7/4�19 
PY  - 1986///
CY  - New York
PB  - W.H. Freeman
KW  - Mathematical recreations
ER  -