Mohd Zubir, M. Z. I., & Wan Abdul Rahman, W. M. W. (2021). Alternative Soundproof Material to Reduce Noise HVAC Round Duct System (Rockwool and Bamboo Fiber). Progress in Engineering Application and Technology, 2(1), 683-693. https://publisher.uthm.edu.my/periodicals/index.php/peat/article/view/722