%0 Journal Article %A N. I. Popivanov %T Equations of mixed type with two lines of degeneracy in unbounded domains. II.~Existence of a strong solution %J Differencialʹnye uravneniâ %D 1978 %P 665-679 %V 14 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1978_14_4_a10/ %G ru %F DE_1978_14_4_a10