TY - JOUR AU - G. M. Kesel'man TI - The spectral property of a perturbed Sturm–Liouville operator with nonlocal boundary conditions JO - Differencialʹnye uravneniâ PY - 1985 SP - 494 EP - 499 VL - 21 IS - 3 UR - http://geodesic.mathdoc.fr/item/DE_1985_21_3_a15/ LA - ru ID - DE_1985_21_3_a15 ER -