@article{IVM_2001_4_a11,
     author = {Vit. V. Volchkov},
     title = {A~local two-radii theorem for $\mathcal M$-harmonic functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {65--68},
     publisher = {mathdoc},
     number = {4},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2001_4_a11/}
}