Warokka, Adriyan, and Artian Sirun. 2018. “Manufacture of Coconut Shell Charcoal Briquettes Results of Pyrolysis Process”. JURNAL TEKNOLOGI INFRASTRUKTUR BERKELANJUTAN (JTIB) 1 (1). Manado, Indonesia:52-61. http://p3m.polimdo.ac.id/jurnal/index.php/JTIB/article/view/Warokka.