@article{DE_1988_24_4_a24,
     author = {O. M. Penkin and Yu. V. Pokornyi},
     title = {On a boundary value problem on a graph},
     journal = {Differencialʹnye uravneni\^a},
     pages = {701--703},
     publisher = {mathdoc},
     volume = {24},
     number = {4},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_4_a24/}
}