Djurdjevic, Dragan, Jovana Todorovic, Zorica Terzic-Supic, and Pavle Piperac. 2022. “Factors Associated With PA Level During the COVID-19 Outbreak in Serbia”. Puerto Rico Health Sciences Journal 41 (2):63-67. https://prhsj.rcm.upr.edu/index.php/prhsj/article/view/2609.