TY  - JOUR
AU  - É. G. Belaga
TI  - A certain interpretation of the 4-coloring of a~planar graph
JO  - Trudy Matematicheskogo Instituta imeni V.A. Steklova
PY  - 1972
VL  - 27
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/RM_1972_27_3_a7/
LA  - ru
ID  - RM_1972_27_3_a7
ER  -