@article{SM_1981_38_1_a4,
     author = {V. I. Feigin},
     title = {The asymptotic distribution of eigenvalues and a~formula of {Bohr--Sommerfeld} type},
     journal = {Sbornik. Mathematics},
     pages = {61--81},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1981},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1981_38_1_a4/}
}