@article{SM_1970_11_1_a1,
     author = {G. S. Litvinchuk and A. P. Nechaev},
     title = {A~generalized {Carleman} boundary value problem},
     journal = {Sbornik. Mathematics},
     pages = {25--45},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1970},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1970_11_1_a1/}
}