VELINOVA, R. Digitalisation of Business in the 21st Century: Evolution of Key Performance Indicators (KPI). Language and Public Sphere, [S. l.], n. 13, p. 119–124, 2024. DOI: 10.33919/LPS.24.13.13. Disponível em: https://ojs.nbu.bg/index.php/LPS/article/view/1299. Acesso em: 7 dec. 2025.