@article{DAN_1979_245_1_a3,
     author = {V. F. Lazutkin},
     title = {An estimate of the length of the gaps in the spectrum of the {Laplace} operator for a plane convex domain},
     journal = {Doklady Akademii Nauk},
     pages = {20--23},
     publisher = {mathdoc},
     volume = {245},
     number = {1},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_245_1_a3/}
}