TY  - BOOK
AU  - Fritsch, Rudolf
AU  - Fritsch, Gerda
AU  - Peschke, Julie, tr.
TI  - Four-color theorem: history, topological foundations and idea of proof
SN  - 0387984976
U1  - 514.2 
PY  - 1998///
CY  - New York
PB  - Springer
ER  -