Fitriadi, Nuzuli, and Edi Saputra. “Rancang Bangun Ketel Pala Dengan Sistem Water Tube”. Jurnal Inotera 2, no. 1 (August 8, 2017): 42-48. Accessed December 6, 2020. https://inotera.poltas.ac.id/index.php/inotera/article/view/19.