TY  - BOOK
AU  - Saaty Thomas L
AU  - Kainen Paul C
TI  - Four-color problem : assaults and conquest
SN  - 0-07-054382-8
U1  - 511.5 
PY  - 1977///
CY  - NY
PB  - McGraw Hill International
KW  - Algebra
KW  - Four-color problem
ER  -