[1]
Uddin, M.A. and Sattar, M.A. 2011. Second Approximate Solution of Duffing Equation with Strong Nonlinearity by Homotopy Perturbation Method. GANIT: Journal of Bangladesh Mathematical Society. 30, (Aug. 2011), 59–75. DOI:https://doi.org/10.3329/ganit.v30i0.8504.