TY - JOUR AU - A. Kh. Stash TI - Properties of Sergeev oscilation characteristics of periodic second-order equation JO - Vladikavkazskij matematičeskij žurnal PY - 2021 SP - 78 EP - 86 VL - 23 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/VMJ_2021_23_2_a6/ LA - ru ID - VMJ_2021_23_2_a6 ER -