Periodicity in a logistic type system with several delays

With the help of a continuation theorem based on Gaines and Mawhinʹs coincidence degree, easily verifiable criteria are established for the global existence of positive periodic solutions of the following several delays logistic type system: where a(t), bj(t) are positive periodic continuous functions with periodic ω > 0, τj (t) are nonnegative continuous periodic functions with periodic ω > 0. After that, by constructing a suitable Lyapunov functional, some sufficient conditions which guarantee the stability of the positive periodic solutions are obtained..