TY  - BOOK
AU  - Vout,Colin
AU  - Gray,Gordon
TI  - Challenging puzzles
SN  - 0521446023
U1  - 793.74 VOU 
PY  - 1993///
CY  - Cambridge, New York
PB  - Cambridge University Press
KW  - Mathematical recreations
KW  - Puzzles
N2  - Designed for all recreational mathematicians from the age of 14 upwards. There are 100 puzzles in all, graded according to difficulty, with hints and solutions to most and suggestions for open ended topics where exact solutions are impossible
ER  -