TY  - JOUR
AU  - N. A. Izobov
TI  - A refinement of the estimate in the freezing method for a two-dimensional system with coincident characteristic numbers
JO  - Differencialʹnye uravneniâ
PY  - 1971
SP  - 990
EP  - 996
VL  - 7
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1971_7_6_a4/
LA  - ru
ID  - DE_1971_7_6_a4
ER  -