Boyanov, Petar. “Content of Vol. 20, 2021, Journal Scientific and Applied Research: Content of Vol. 20, 2021, Journal Scientific and Applied Research”. JOURNAL SCIENTIFIC AND APPLIED RESEARCH 20, no. 1 (March 23, 2023): 3. Accessed November 7, 2024. https://jsar.ftn.shu.bg/ojs-3.3.0-7/index.php/jsar/article/view/297.