Fatra, Warman, Randi Sanjaya, Zulfansyah Zulfansyah, Hari Rionaldo, and Zuchra Helwani. 2015. “Alkaline Treatment of Oil Palm Frond Fibers by Using Extract of Oil Palm EFB Ash for Better Adhesion Toward Polymeric Matrix”. Journal of Engineering and Technological Sciences 47 (5):498-507. https://doi.org/10.5614/j.eng.technol.sci.2015.47.5.3.