Shith, Syabiha. “Multivariate Analysis on Trace Elements of Fine Particulate Matter (PM2.5) in Industrial and Sub-Urban Area”. International Journal of Integrated Engineering 11, no. 2 (May 6, 2019). Accessed May 3, 2024. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/4119.