OKONKWO E. M., O. E. M. Optimization of Biodiesel Production: Transesterification of Edible and Non-Edible Vegetable Oils : Transesterification of Edible and Non-Edible Vegetable Oils . Journal of Energy Policy Research and Development (JEPRD), v. 1, n. 1, p. 119-129, 1 Mar. 2011.