A note on He's homotopy perturbation method for van der Pol oscillator with very strong nonlinearity

In this paper, He's homotopy perturbation method combined with averaging is applied to van der Pol oscillator with very strong nonlinearity. The result reveals that approximation obtained by this approach is valid uniformly even for very large parameters and is more accurate than straightforward expansion solution. (C) 2006 Elsevier Ltd. All rights reserved.