Al-Ajlan A. Measuring Time, Cost, Complexity, Quality, and Security of Ten Free E-Learning Platforms and Their Compliance with Lehman’s Eight Laws. JAES [انترنت]. 30 سبتمبر، 2025 [وثق 7 أكتوبر، 2025];18(2):585-606. موجود في: https://jaes.qu.edu.sa/index.php/jae/article/view/2652