Existence and uniqueness of periodic solutions for a kind of first order neutral functional differential equations

In this paper, we use the coincidence degree theory to establish new results on the existence and uniqueness of T -periodic solutions for the first order neutral functional differential equation of the form x(t) +Bx(t − δ) = g1 t,x(t) +g2 t,x(t −τ) + p(t). © 2005 Elsevier Inc. All rights reserved