Hussain, Zakir, Deepa Meghavathu, and Rakesh Kumar. “Effect of Quaternary Ammonium Salt Addition to Conventional Biodiesel Production Process”. International Journal of Engineering & Technology 7, no. 4.5 (September 22, 2018): 220–223. Accessed May 2, 2024. https://www.sciencepubco.com/index.php/ijet/article/view/20050.