%0 Journal Article %A A. V. Bitsadze %T On some classes of exact solutions of the gravitational field equations %J Doklady Akademii Nauk %D 1977 %P 517-518 %V 233 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1977_233_4_a1/ %G ru %F DAN_1977_233_4_a1