@article{MAT_1963_7_6_a4,
     author = {G. Fichera},
     title = {On a unified theory of boundary value problems for elliptic-parabolic equations of second order},
     journal = {Matematika},
     pages = {99--122},
     year = {1963},
     volume = {7},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MAT_1963_7_6_a4/}
}