Boyanov, Petar. “Content of Vol. 19, 2020, Journal Scientific and Applied Research: Content of Vol. 19, 2020, Journal Scientific and Applied Research”. JOURNAL SCIENTIFIC AND APPLIED RESEARCH 19, no. 1 (March 23, 2023): 3. Accessed November 22, 2024. https://jsar.ftn.shu.bg/ojs-3.3.0-7/index.php/jsar/article/view/286.