@article{TRSPY_1971_116_a8,
     author = {O. A. Ladyzhenskaya and L. Stupyalis},
     title = {Boundary value problems for equations of mixed type},
     journal = {Informatics and Automation},
     pages = {101--136},
     publisher = {mathdoc},
     volume = {116},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1971_116_a8/}
}