KYSIL T.; NECHUYVITER M. Information technology for comparing distance learning services. Computer systems and information technologies, [S. l.], n. 2, p. 59–63, 2020. DOI: 10.31891/CSIT-2020-2-9. Disponível em: https://csitjournal.khmnu.edu.ua/index.php/csit/article/view/26. Acesso em: 10 apr. 2025.