Stability of the periodic motions of autonomous systems with lag

In the article we give a generalization of the theorem of A. A. Andronov and A. A. Vitt on the stability of the periodic motions of autonomous systems described by ordinary differential equations to autonomous time-lag systems. The investigation is based on the procedures developed by N. N. Krasovskii which consider the differential equations with lag in a functional space of continuous functions. There is a bibliography of eight items.Translated from Matematicheskie Zametki, Vol. 2, No. 5, pp.561–568, November, 1967.