@article{DE_1971_7_12_a7,
     author = {I. Zeman},
     title = {A remark on {Tihonov's} theorem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2187--2190},
     year = {1971},
     volume = {7},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1971_7_12_a7/}
}