Chkhartishvili, A., Gubanov, D. and Kozitsin, I. (2021) “Face Mask Perception during the COVID-19 Pandemic: an Observational Study of Russian Online Social Network VKontakte”, Advances in Systems Science and Applications, 21(3), pp. 91-100. doi: 10.25728/assa.2021.21.3.1124.