Digital economy and problems of security of Ukrainian trade and entertainment centers. Mathematical Machines and Systems, [S. l.], n. 1, p. 60–71, 2023. DOI: 10.34121/1028-9763-2023-1-60–71. Disponível em: https://www.j-mms.de/index.php/mms/article/view/2023-1-a4. Acesso em: 11 aug. 2026.