TY  - BOOK
AU  - Ball,W.W.Rouse
TI  - Mathematical recreations & essays
AV  - QA95 .B2 1939
U1  - 510.76 
PY  - 1931///
CY  - London
PB  - The Macmillan company
KW  - Mathematical recreations
KW  - Local
KW  - Ciphers
KW  - Cryptography
KW  - Geometry
KW  - Problems, Famous
N1  - Includes bibliographical footnotes and index
ER  -