%0 Journal Article %A D. Z. Kagan %T Nontrivial pseudocharacters on groups with one defining relation and nontrivial centre %J Sbornik. Mathematics %D 2017 %P 75-89 %V 208 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_2017_208_1_a3/ %G en %F SM_2017_208_1_a3