Value Added and Capital Efficiency in Green and Brown Bulgarian Energy Companies. International Journal of Business Innovation, [S. l.], v. 1, n. 3, p. e30186, 2022. DOI: 10.34624/ijbi.v1i3.30186. Disponível em: https://proa.ua.pt/index.php/ijbi/article/view/30186. Acesso em: 12 feb. 2026.