@article{DE_1990_26_10_a13,
     author = {L. M. Fridman},
     title = {Singular redefinitions of discontinuous systems, and stability},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1759--1765},
     publisher = {mathdoc},
     volume = {26},
     number = {10},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_10_a13/}
}