GATOVSKI, I. . INCREASING THE ECOLOGICAL LEVEL OF PUBLIC TRANSPORT IN THE CITY OF SOFIA. Proceedings of CBU in Economics and Business, [S. l.], v. 1, p. 57-61, 2020. DOI: 10.12955/peb.v1.19. Disponível em: https://ojs.cbuic.cz/index.php/peb/article/view/19. Acesso em: 5 nov. 2026.