@article{UZMU_1959_186_186_a13,
     author = {Kh. G. Tsvang},
     title = {Singular points of a~differential equation with lagging argument},
     journal = {Uchenye Zapiski Moskovskogo Gosudarstvennogo Universiteta},
     pages = {211--218},
     year = {1959},
     volume = {186},
     number = {186},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZMU_1959_186_186_a13/}
}