SULAIMAN ALROMAIH , M. .; MAHDI HASSAN , M. . COVAC: A Blockchain-based COVID Testing and Vaccination Tracking System. International Journal of Science, Technology & Management, [S. l.], v. 3, n. 3, p. 703–714, 2022. DOI: 10.46729/ijstm.v3i3.496. Disponível em: https://www.ijstm.inarah.co.id/index.php/ijstm/article/view/496. Acesso em: 24 dec. 2025.