@article{ZNSL_1973_38_a3,
     author = {E. M. Il'in},
     title = {Singularities of weak solutions of elliptic boundary value problems with discontinuous coefficients},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {33--45},
     publisher = {mathdoc},
     volume = {38},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1973_38_a3/}
}