@article{DE_1980_16_10_a16,
     author = {N. N. Golub},
     title = {Necessary conditions for optimality for multidimensional distributed systems containing units with lumped parameters},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1878--1881},
     publisher = {mathdoc},
     volume = {16},
     number = {10},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_10_a16/}
}