SMATKOV, S.; KUCHUK, N. MATHEMATICAL MODEL OF E-LEARNING TRANSACTION PROCESS. Information and Telecommunication Sciences, [S. l.], n. 1, p. 43–48, 2018. DOI: 10.20535/2411-2976.12018.43-48. Disponível em: https://infotelesc.kpi.ua/article/view/136556. Acesso em: 8 oct. 2025.