%0 Journal Article %A A. V. Bitsadze %A A. M. Nakhushev %T Correct formulations of problems for equations of mixed type in multidimensional domains %J Doklady Akademii Nauk %D 1972 %P 9-12 %V 205 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1972_205_1_a0/ %G ru %F DAN_1972_205_1_a0