%0 Journal Article %A S. B. Sorokin %T Error bounds of two-sided approximations for the Sturm--Liouville problem %J Sibirskij žurnal vyčislitelʹnoj matematiki %D 2000 %P 73-88 %V 3 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/SJVM_2000_3_1_a4/ %G ru %F SJVM_2000_3_1_a4