@article{DE_1978_14_7_a7,
     author = {N. Satimov},
     title = {The composition of a differential equation from its solutions, and the proof of a lemma of {L.\,S.~Pontrjagin}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1208--1214},
     publisher = {mathdoc},
     volume = {14},
     number = {7},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_7_a7/}
}