Hamzah, Nurhidayah, et al. “The Measurement of PM10 and PM2.5 Concentration for Outdoor and Indoor Surrounding Industrial Area”. Journal of Advancement in Environmental Solution and Resource Recovery, vol. 1, no. 1, Dec. 2021, pp. 9-17, https://penerbit.uthm.edu.my/ojs/index.php/jaesrr/article/view/9859.