Reply to Comment on 'Analytical approach for solving population balances: a homotopy perturbation method' (2019) J. Phys. A: Math. Theor. 52 385201 Breadcrumbs UL Home Research Year of Publication 2020 Publisher IOP PUBLISHING LTD Journal Journal Of Physics A-Mathematical And Theoretical DOI 10.1088/1751-8121/ab8e65