%0 Journal Article %A F. E. Lomovtsev %T Smoothness of Strong Solutions of Complete Hyperbolic Second-Order Differential Equations with Variable Domains of Operator Coefficients %J Differencialʹnye uravneniâ %D 2001 %P 276-278 %V 37 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2001_37_2_a15/ %G ru %F DE_2001_37_2_a15