%0 Journal Article
%A V. A. Sadovnichii
%A V. E. Podolskii
%T A~class of Sturm--Liouville operators and approximate calculation of the first eigenvalues
%J Sbornik. Mathematics
%D 1998
%P 129-145
%V 189
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1998_189_1_a6/
%G en
%F SM_1998_189_1_a6