@article{MMO_1973_28_a0,
     author = {M. \v{S}. Birman and M. Z. Solomyak},
     title = {Spectral asymptotics of nonsmooth elliptic {operators.~I,~II}},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {3--34},
     publisher = {mathdoc},
     volume = {28},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1973_28_a0/}
}