@article{RM_1983_38_1_a27,
     author = {E. V. Sevost'yanova},
     title = {On~properties of a perturbed elliptic operator with periodic coefficients},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {217--218},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1983},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1983_38_1_a27/}
}