TY  - BOOK
AU  - Saaty,Thomas L
AU  - Kainen,Paul C.
TI  - The four-color problem: assaults and conquest
SN  - 0070543828
PY  - 1977///
CY  - New York
PB  - McGraw-Hill International Book
KW  - Four
KW  - color problem
N1  - Includes index; Bibliography: p. 197-211
ER  -