@article{DE_1990_26_12_a22,
     author = {V. V. Mityushev},
     title = {A functional equation for harmonic functions in a multiply connected domain},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2176--2178},
     publisher = {mathdoc},
     volume = {26},
     number = {12},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_12_a22/}
}