Warokka, Adriyan, and Artian Sirun. “Manufacture of Coconut Shell Charcoal Briquettes Results of Pyrolysis Process”. JURNAL TEKNOLOGI INFRASTRUKTUR BERKELANJUTAN (JTIB) 1, no. 1 (July 31, 2018): 52-61. Accessed September 19, 2021. http://p3m.polimdo.ac.id/jurnal/index.php/JTIB/article/view/Warokka.