Frequency analysis of strongly nonlinear generalized Duffing oscillators using He's frequency-amplitude formulation and He's energy balance method. - Davood Younesian; Hassan Askari; Zia Saadatnia; Mohammad Kalami Yazdi (Comput. Math. Appl., 2010)

Higher order approximate periodic solutions for nonlinear oscillators with the Hamiltonian approach. - Ahmet Yildirim; Zia Saadatnia; Hassan Askari; Yasir Khan; Mohammad Kalami Yazdi (Appl. Math. Lett., 2011)

Approximate periodic solutions for the Helmholtz-Duffing equation. - Hassan Askari; Zia Saadatnia; Davood Younesian; Ahmet Yildirim; M. Kalami Yazdi (Comput. Math. Appl., 2011)

Corrigendum to "Analysis of nonlinear oscillations of a punctual charge in the electric field of a charged ring via a Hamiltonian approach and the energy balance method" [Computers & Mathematics with Applications 62 (2011) 486-490]. - M. Kalami Yazdi (Comput. Math. Appl., 2011)

Analysis of nonlinear oscillations of a punctual charge in the electric field of a charged ring via a Hamiltonian approach and the energy balance method. - Ahmet Yildirim; Hassan Askari; Zia Saadatnia; Mohammad Kalami Yazdi; Yasir Khan (Comput. Math. Appl., 2011)

A relationship between three analytical approaches to nonlinear problems. - Ahmet Yildirim; Hassan Askari; M. Kalami Yazdi; Yasir Khan (Appl. Math. Lett., 2012)