“…Many nonlinear problems do not contain such perturbation quantity, so to overcome the shortcomings, many new techniques have appeared in open literature such as; harmonic balance (Hamdan & Shabaneh 1997), homotopy perturbation (Barari et al 2008;He 2004;Özis & Yildirim 2007a), modified Lindstedt-Poincaré (He 2001;He 2002b;Özis & Yildirim 2007b;Mohammadi et al 2009), Adomian decomposition (Dehghan & Shakeri 2008), amplitude-frequency formulation , parameterexpansion , parameterized perturbation (He 1999a), multiple scale (Okuizumi & Kimura 2004), energy balance (He 2006a;Momeni et al 2010), variational approach (He 2007;Xu 2008;Tolou et al 2009;Hashemi Kachapi et al 2009), Variational Iteration (He et al 2010;Herisanu & Marinca 2010), Newton-harmonic balancing (Lai et al 2009), differential transformation (Catal 2008), max-min (He 2008;Zeng & Lee 2009;Zeng 2009;Shen & Mo 2009).…”