SMIGIELSKI, KEN, and FARHANG AKBAR-KHANZADEH. “Characteristics, Pressure Drop and Capture Efficiency of Heavily Loaded New and Repeatedly Washed HEPA Filters”. International Journal of Occupational Hygiene 10, no. 2 (July 24, 2018). Accessed December 11, 2018. http://ijoh.tums.ac.ir/index.php/ijoh/article/view/328.