%0 Journal Article
%A M. Kierlańczyk
%T On a differential inequality of the type \(X'' + f(t)X \geq 0\)
%J Commentationes Mathematicae
%D 1979
%P  325-326
%V 21
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.14708/cm.v21i2.5992/
%R 10.14708/cm.v21i2.5992
%G pl
%F 10_14708_cm_v21i2_5992