The effect of financial leverage on the profitability of economic services companies - Case study of the Sonelgaz company in Guelma for the period )2017-2019(. Alijtihed Journal on Legal and Economic Studies, [S. l.], v. 12, n. 01, p. 504–523, 2023. DOI: 10.36540/4kq4jf56. Disponível em: https://alijtihed.univ-tam.dz/article/view/140.. Acesso em: 30 jul. 2025.