@article{SM_1977_33_1_a4,
     author = {S. N. Kruzhkov and S. M. Sukoryanskii},
     title = {Boundary value problems for systems of equations of two-phase porous flow type; statement of the problems, questions of solvability, justification of approximate methods},
     journal = {Sbornik. Mathematics},
     pages = {62--80},
     publisher = {mathdoc},
     volume = {33},
     number = {1},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1977_33_1_a4/}
}