@article{DE_1983_19_5_a5,
     author = {V. T. Erofeenko},
     title = {Addition theorems and integral transformations on classes of harmonic functions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {809--818},
     year = {1983},
     volume = {19},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1983_19_5_a5/}
}