The head on collision of ion- acoustic solitary waves (IASWs) in a magnetized plasma are considered. The two- sides Korteweg-de Vries (KdV) equations in generic case as well as the two- sides modified Korteweg-de Vries (mKdV) equations in a special case are obtained.The analytical phase shifts and the trajectories after the Head-on collisions of two IASWs in a three species quantum plasma are derived by using the extended version of Poincare-Lighthill-Kuo (PLK) method for both the situations.

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... e conservation laws for KdV and mKdV equations are obtained. By applying the extended direct algebraic method, we found the traveling wave solutions for the two-sides KdV and mKdV equations.