@article{01597804,
title = {Gaps in the chromatic spectrum of face-constrained plane graphs.},
journal = {The Electronic Journal of Combinatorics [electronic only]},
volume = {8},
year = {2001},
zbl = {0984.05036},
language = {en},
url = {http://dml.mathdoc.fr/item/01597804}
}
Kobler, Daniel; Kündgen, André. Gaps in the chromatic spectrum of face-constrained plane graphs.. The Electronic Journal of Combinatorics [electronic only], Tome 8 (2001) . http://gdmltest.u-ga.fr/item/01597804/