@article{SM_1977_31_1_a6,
     author = {V. I. Gorbachuk and M. L. Gorbachuk},
     title = {Boundary values of solutions of some classes of differential equations},
     journal = {Sbornik. Mathematics},
     pages = {109--133},
     publisher = {mathdoc},
     volume = {31},
     number = {1},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1977_31_1_a6/}
}