MT, Yusrizal, Muhammad Ali, Nuzuli Fitriadi, Irwansyah Syam, Balkhaya, and Herdi Susanto. “Marble Powder Blended Utilization Polyurethane As Soundproof Materials”. Jurnal Inotera 6, no. 1 (February 2, 2021): 30-36. Accessed August 2, 2021. https://inotera.poltas.ac.id/index.php/inotera/article/view/131.