Sulaiman, Muhammad Syahir, and WAN MOHD WARDI WAN ABDUL RAHMAN. “Study of Potential of Polyethylene Foam As Sound Insulation for HVAC Rectangular Duct”. Progress in Engineering Application and Technology 2, no. 1 (June 22, 2021): 779–786. Accessed July 18, 2024. https://penerbit.uthm.edu.my/periodicals/index.php/peat/article/view/716.