Purwanto, B., Aryantie, M. H., Zulfachmi, Z. and Aprishanty, R. (2020) “Low-Cost and Portable Sound Reduction Box: Innovation for Acoustic Material Performance Measurement”, Journal of Engineering and Technological Sciences, 52(5), pp. 732-744. doi: 10.5614/j.eng.technol.sci.2020.52.5.9.