@article{IM2_1989_33_2_a9,
     author = {N. S. Nadirashvili},
     title = {Some estimates in a~problem with oblique derivative},
     journal = {Izvestiya. Mathematics},
     pages = {403--411},
     year = {1989},
     volume = {33},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1989_33_2_a9/}
}