@article{TMF_1994_99_1_a1,
     author = {A. A. Kiselev and B. S. Pavlov},
     title = {Essential spectrum of the {Laplacian} for the {Neumann} problem in a~model region of complicated structure},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {3--19},
     publisher = {mathdoc},
     volume = {99},
     number = {1},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1994_99_1_a1/}
}