@article{DE_1990_26_2_a23,
     author = {I. U. Zulkarnaev},
     title = {Solution of a boundary value problem for {Poisson} and {Laplace} equations with boundary conditions of the fourth kind on concentric boundaries of constant radius},
     journal = {Differencialʹnye uravneni\^a},
     pages = {351--353},
     publisher = {mathdoc},
     volume = {26},
     number = {2},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_2_a23/}
}