%0 Journal Article %A È. V. Kissin %A V. S. Shulman %T Representations of Nilpotent Groups: Extensions, Neutral Cohomology, and Pontryagin Spaces %J Funkcionalʹnyj analiz i ego priloženiâ %D 2015 %P 79-83 %V 49 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/FAA_2015_49_3_a8/ %G ru %F FAA_2015_49_3_a8