%0 Journal Article %A M. A. Naimark %T Conditions for unitary equivalence of commutative symmetric algebras in the space $\Pi_k$ %J Doklady Akademii Nauk %D 1965 %P 1257-1260 %V 160 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1965_160_6_a8/ %G ru %F DAN_1965_160_6_a8