TY  - BOOK
AU  - Fritsch,R & Fritsch,G
ED  - Fritsch, G
TI  - Four-color theorem: history, topological foundations, & idea of proof
SN  - 9780387984971
U1  - 2.08 
PY  - 1998///
CY  - New York
PB  - Springer
ER  -