Qureshi, M.I.Hashmi, M.A.ZiauddinIqbal, S.2018-01-092018-01-092017-09Journal of the National Science Foundation of Sri Lanka,45(3):p.337-346https://dl.nsf.gov.lk/handle/1/23583Homotopy perturbation methodNumerical solution/Obstacle problemSystem of boundary value problemA study of obstacle problems using homotopy perturbation methodArticle