N.A. Razak, M.H.M. Hanafi, N.H. Razak, A. Ibrahim, A.A. Omar, Characterization of Waste Cooking Oil Purified by Crushed and Sliced Zingiber Officinale (Ginger), Chemical Engineering Transactions. 94 (2022) 337-342. doi:10.3303/CET2294056.