Purwanto, Budi, Melania Hanny Aryantie, Zulfachmi Zulfachmi, and Rina Aprishanty. 2020. “Low-Cost and Portable Sound Reduction Box: Innovation for Acoustic Material Performance Measurement”. Journal of Engineering and Technological Sciences 52 (5):732-44. https://doi.org/10.5614/j.eng.technol.sci.2020.52.5.9.