The generalized tanh-coth method to special types of the fifth-order KdV equation

In this paper we use a generalization of the well-known tanh-coth method to obtain new periodic and soliton solutions for several forms of the fifth-order KdV equation (fKdV). Three special cases that we consider here are the Caudrey-Dodd-Gibbon (CDG), the generalized Kaup-Kupershmidt (GKK) and the generalized Ito equations. New traveling wave solutions which include periodic and soliton solutions for three cases are formally derived.