@article{DE_1985_21_9_a18,
     author = {G. M. Amatova},
     title = {Singular points of systems with shocks},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1613--1615},
     publisher = {mathdoc},
     volume = {21},
     number = {9},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_9_a18/}
}