Filtration efficiency of face masks and veils as protective measures during COVID-19 pandemic - khaled Al-hadyan; Ghazi A. Alsbeih; Najla M. Al-Harbi; Sara S. Bin Judia; Maha M. Al-Ghamdi; Salem M. Al-Ghamdi; Belal A. Moftah; Rashed S. Alhmaid (Kuwait Journal of Science)