“…Recently, a few studies on permanence of general nonautonomous impulsive systems (1) and (2) and their special cases were made in [1,5,20,21,2,6,7,23,24,12,[25][26][27][28]30,31,35,17,36,18,4]. Therefore, applying Theorem 1 and Corollary 1 of this paper we obviously can obtain that if systems are ω-periodic, then there is at least one positive ω-periodic solution under the permanent conditions.…”