TY - JOUR AU - Yu. E. Karpeshina TI - Perturbation theory for the Schr\"odinger operator with periodic potential JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1990 SP - 88 EP - 116 VL - 188 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1990_188_a4/ LA - ru ID - TM_1990_188_a4 ER -