%0 Journal Article %A M. A. Naǐmark %T Conditions for the unitary equivalence of commutative symmetric algebras in the Pontrjagin space~$\Pi_k$ %J Trudy Moskovskogo matematičeskogo obŝestva %D 1966 %P 383-399 %V 15 %I mathdoc %U http://geodesic.mathdoc.fr/item/MMO_1966_15_a10/ %G ru %F MMO_1966_15_a10