@article{FAA_1970_4_4_a0,
     author = {M. Sh. Birman and M. Z. Solomyak},
     title = {Leading term in the asymptotic spectral formula for ``nonsmooth'' elliptic problems},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {1--13},
     publisher = {mathdoc},
     volume = {4},
     number = {4},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1970_4_4_a0/}
}