@article{DE_1984_20_4_a14,
     author = {O. N. Litvin},
     title = {Optimal coordinate functions in the finite element method},
     journal = {Differencialʹnye uravneni\^a},
     pages = {677--688},
     publisher = {mathdoc},
     volume = {20},
     number = {4},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_4_a14/}
}