"Measuring the Degree of the Effect of the Financial and Operating Leverages on the Earning per Share in the Energy Companies", renaf, م 19, عدد 32, ص 91–110, يوليو 2025, تاريخ الوصول: أكتوبر 22, 2026. موجود في: https://journals.univ-chlef.dz/index.php/renaf/article/view/522