M. Kamal, N.A.A. and Ibrahim, S.A. (2024) “Producing a Liquid Soap by Adding Lemon Extract from Used Cooking Oil for Multipurpose Cleaning Use”, Research Progress in Mechanical and Manufacturing Engineering, 5(1), pp. 378–386. Available at: https://publisher.uthm.edu.my/periodicals/index.php/rpmme/article/view/16803 (Accessed: 12 March 2026).