@article{SM_1989_63_2_a0,
     author = {V. A. Bulychev and F. F. Frolov},
     title = {Boundary value problems for generalized differential equations},
     journal = {Sbornik. Mathematics},
     pages = {267--287},
     publisher = {mathdoc},
     volume = {63},
     number = {2},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1989_63_2_a0/}
}