D. . Santi, A. . Muin, and A. D. N. . Lestari, “Determination of Major Cation and Anion Content in Coconut Fiber Ash Potentially Renewable Catalyst: Penentuan Kandungan Kation dan Anion Mayor dalam Abu Serabut Kelapa Berpotensi Katalis Renewable”, JISTECH, vol. 6, no. 2, Jan. 2023.