Ernawati, K. E.; Jannah, F.; Qodriyyah Sani, F.; Rizki Pratami, A.; Eri Cahyani, D.; Isdiharana, K.; Syah Putra, M. F. The Effect of Online Education on Knowledge about Covid-19 Masks in High School Students in Jakarta: A Pre-Experiment Study. KSS 2022, 7, 403-412.