Positive periodic solutions of a periodic neutral delay logistic equation with impulses

By using a fixed point theorem of strict-set-contraction, some criteria are established for the existence of positive periodic solutions for a periodic neutral functional differential equation with impulses of the form {dx(t)dt=x(t)[a(t)−∑i=1mbi(t)x(t−τi(t))−∑j=1ncj(t)x′(t−σj(t))],x(tk+)−x(tk)=−Ik(x(tk)),k=1,2,….