@article{DE_1976_12_3_a13,
     author = {I. V. Fryazinov},
     title = {A certain difference approximation of the {Poisson} equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {540--548},
     publisher = {mathdoc},
     volume = {12},
     number = {3},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_3_a13/}
}