Shamil Z, Valiev, y Aida Kh Talipova. «Enhancing Accessibility of Higher Education through the System of Educational Credits». Opción 350 (junio 9, 2019): 1031-1056. Accedido junio 11, 2025. https://mail.produccioncientificaluz.org/index.php/opcion/article/view/24072.