TY - JOUR AU - N. A. Izobov TI - Half periods of the solutions of two-dimensional linear systems JO - Differencialʹnye uravneniâ PY - 1975 SP - 782 EP - 797 VL - 11 IS - 5 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DE_1975_11_5_a1/ LA - ru ID - DE_1975_11_5_a1 ER -