@article{IM2_2012_76_2_a6,
     author = {O. A. Ochakovskaya},
     title = {Theorems on ball mean values for solutions of the {Helmholtz} equation on unbounded domains},
     journal = {Izvestiya. Mathematics},
     pages = {365--374},
     year = {2012},
     volume = {76},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2012_76_2_a6/}
}