@article{DE_1990_26_10_a6,
     author = {V. I. Kachalov},
     title = {Smoothness of solutions of differential equations that contain a parameter},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1711--1716},
     publisher = {mathdoc},
     volume = {26},
     number = {10},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_10_a6/}
}