Comment on: “Application of the method for the complex KdV equation” [Huiqun Zhang, Commun Nonlinear Sci Numer Simul 15;2010:1700–1704]

In this letter we analyze the paper by Zhang [1]. Using the improved G ′ / G – expansion method Zhang found “new types of exact travelling wave solutions of the complex KdV equation”. We checked Zhang’s “solutions” and proved that apart from trivial cases none of them satisfy the KdV equation. Moreover, the general solution of the KdV equation in the form of the travelling wave was obtained more than one century ago. We give this solution in this letter for the reference source.