TY  - JOUR
AU  - N. I. Popivanov
TI  - Equations of mixed type with two lines of degeneracy in unbounded domains. I.~Imbedding theorem. Uniqueness theorem
JO  - Differencialʹnye uravneniâ
PY  - 1978
SP  - 304
EP  - 317
VL  - 14
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1978_14_2_a11/
LA  - ru
ID  - DE_1978_14_2_a11
ER  -