TY  - JOUR
AU  - Bowen, Robert
TI  - On Sums of Valencies in Planar Graphs
JO  - Canadian mathematical bulletin
PY  - 1966
SP  - 111
EP  - 114
VL  - 9
IS  - 1
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1966-016-x/
DO  - 10.4153/CMB-1966-016-x
ID  - 10_4153_CMB_1966_016_x
ER  -