TY - JOUR AU - J. Brüning AU - R. V. Nekrasov AU - A. I. Shafarevich TI - Quantization of Periodic Motions on Compact Surfaces of Constant Negative Curvature in a Magnetic Field JO - Matematičeskie zametki PY - 2007 SP - 32 EP - 42 VL - 81 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MZM_2007_81_1_a2/ LA - ru ID - MZM_2007_81_1_a2 ER -