Dobrzyński, Michał, Jakub Czarnota, Dorota Sokół, Tomasz Skubel, Arkadiusz Standyło, and Halina Piecewicz-Szczęsna. 2019. “Zinc Lozenges Efficacy in Cold Treatment”. Journal of Education, Health and Sport 9 (9):299-305. https://apcz.umk.pl/JEHS/article/view/7395.