%0 Journal Article %A V. I. Paasonen %T The improved boundary conditions at the singular points of coordinate systems for non-stationary boundary value problems %J Sibirskij žurnal vyčislitelʹnoj matematiki %D 1999 %P 373-384 %V 2 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/SJVM_1999_2_4_a6/ %G ru %F SJVM_1999_2_4_a6