@article{DE_1973_9_10_a4,
     author = {I. P. Martynov},
     title = {Differential equations with fixed critical singular points},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1780--1791},
     publisher = {mathdoc},
     volume = {9},
     number = {10},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_10_a4/}
}