On the factorization of a certain class of entire functions

Let P and Q be polynomial, alpha be an entire function with bounded singular values, and h be a periodic entire function with period 2 pi and with ore one. By (n) (z) we denote the nth iteration of P o h o alpha (z). In this paper, we shall prove that if the function F (z) = G(n) (z) + Q (z) has a factorization F(z) = f (g (z)), then g(z) must be a common right factor of alpha(z) and Q(z).