TY  - BOOK
AU  - Northrop,Eugene Purdy
TI  - Reddles in mathematics: a book of paradoxes 
U1  - 152 
PY  - 1945///
CY  - London
PB  - The english universities press
KW  - Mathematics
N1  - Includes bibl; Notes and refences : p. 229-234
ER  -