V.H., R.-H., C.-R. H., and N. A. A. M. “Energy Optimization of Reactive Distillation Columns for Biodiesel by Pinch Point Analysis”. Global Journal of Energy Technology Research Updates, vol. 4, no. 1, Mar. 2017, pp. 1-8, doi:10.15377/2409-5818.2017.04.01.1.