TY  - BOOK
AU  - Gardner, Martin
TI  - Knotted doughnuts and other mathematical entertainments
SN  - 0-7167-1799-9
U1  - 793.74/GAR 
PY  - 1986///
CY  - New York
PB  - W.H. Freeman
KW  - Mathematical recreations
KW  - The arts
ER  -