@article{TM_1953_41_a0,
     author = {A. V. Bitsadze},
     title = {On the problem of equations of mixed type},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {3--59},
     publisher = {mathdoc},
     volume = {41},
     year = {1953},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1953_41_a0/}
}