@article{TSP_2009_27_27_a6,
     author = {S. A. Nazarov},
     title = {Asymptotics of negative eigenvalues of the {Dirichlet} problem with the density changing sign},
     journal = {Trudy Seminara im. I.G. Petrovskogo},
     pages = {235--275},
     publisher = {mathdoc},
     volume = {27},
     number = {27},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TSP_2009_27_27_a6/}
}