@article{IM2_1995_44_1_a8,
     author = {V. V. Volchkov},
     title = {New two-radii theorems in the theory of harmonic functions},
     journal = {Izvestiya. Mathematics},
     pages = {181--192},
     year = {1995},
     volume = {44},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1995_44_1_a8/}
}