@article{MOMA_1975__79_177689,
     author = {Herbert Fleischner},
     title = {Gedanken zur {Vier-Farben-Vermutung.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {201--212},
     publisher = {mathdoc},
     volume = {79},
     year = {1975},
     zbl = {0309.05111},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1975__79_177689/}
}