Nikola, Tanakow, and Tsolov Georgi. “Influence Analysis of The Active Part of Human Resources on The GDP of The Level 2 Regions in Bulgaria”. Finance, Accounting and Business Analysis (FABA) 2, no. 1 (May 2, 2020): 25–34. Accessed June 7, 2026. https://faba.bg/index.php/faba/article/view/31.