@article{MOMA_1980__89_177957,
     author = {U. Krusenstjerna-Hafstrom and B. Toft},
     title = {Special {Subdivisions} of {K4} and {4-Chromatic} {Graphs.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {101--110},
     publisher = {mathdoc},
     volume = {89},
     year = {1980},
     zbl = {0421.05025},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1980__89_177957/}
}