TY  - JOUR
AU  - Tutte, W.T.
TI  - On the Colourings of Graphs
JO  - Canadian mathematical bulletin
PY  - 1961
SP  - 157
EP  - 160
VL  - 4
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1961-019-4/
DO  - 10.4153/CMB-1961-019-4
ID  - 10_4153_CMB_1961_019_4
ER  -