@article{RM_2004_59_5_a10,
     author = {A. A. Kotel'nikova},
     title = {On the gaps in the spectrum of an elliptic operator on a~periodic grid},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {963--965},
     year = {2004},
     volume = {59},
     number = {5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2004_59_5_a10/}
}