@article{GDZPPN00204157X, title = {Chromatic sums revisited.}, journal = {Aequationes mathematicae}, volume = {49}, year = {1995}, pages = {95-134}, zbl = {0842.05031}, url = {http://dml.mathdoc.fr/item/GDZPPN00204157X} }
Tutte, W.T. Chromatic sums revisited.. Aequationes mathematicae, Tome 49 (1995) pp. 95-134. http://gdmltest.u-ga.fr/item/GDZPPN00204157X/