%0 Journal Article %A B. I. Efendiev %T Lyapunov inequality for an ordinary second-order differential equation with a distributed integration operator %J Itogi nauki i tehniki. Sovremennaâ matematika i eë priloženiâ. Tematičeskie obzory %D 2021 %P 133-137 %V 198 %I mathdoc %U http://geodesic.mathdoc.fr/item/INTO_2021_198_a14/ %G ru %F INTO_2021_198_a14