@article{MT_2001_4_2_a7,
     author = {S. G. Pyatkov},
     title = {Elliptic {Eigenvalue} {Problems} {Involving} {an~Indefinite} {Weight} {Function}},
     journal = {Matemati\v{c}eskie trudy},
     pages = {138--154},
     publisher = {mathdoc},
     volume = {4},
     number = {2},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MT_2001_4_2_a7/}
}