%0 Journal Article
%A V. K. Polishchuk
%T On the analytic theory of the equation $z^2u^{''}-f(z)u=0$.~I, II
%J Differencialʹnye uravneniâ
%D 1972
%P 1999-2011
%V 8
%N 11
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1972_8_11_a11/
%G ru
%F DE_1972_8_11_a11