%0 Journal Article %A P. E. Sobolevskii %T Parabolic equations in a Banach space with an unbounded variable operator, a fractional power of %J Doklady Akademii Nauk %D 1961 %P 59-62 %V 138 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1961_138_1_a15/ %G ru %F DAN_1961_138_1_a15