@article{DE_1978_14_5_a21,
     author = {V. D. Ponomarev},
     title = {Necessary and sufficient conditions for the solvability of a multipoint boundary value problem for a system of first order ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {929--931},
     publisher = {mathdoc},
     volume = {14},
     number = {5},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_5_a21/}
}