Sibagariang, Yogie Probo, Farel Hasiholan Napitupulu, Hideki Kawai, and Himsar Ambarita. “Preliminary Test of Double Slope Solar Still Integrating With Oil Palm Shells”. ITB Graduate School Conference 3, no. 1 (October 18, 2023): 692–699. Accessed December 7, 2025. https://gcs.itb.ac.id/proceeding-igsc/index.php/igsc/article/view/185.