A SECURE E - COUPON SERVICE BASED ON BLOCK CHAIN SYSTEM . Phoenix: International Multidisciplinary Research Journal ( Peer reviewed High Impact Journal ), [S. l.], v. 1, n. 3, p. 63–67, 2023. Disponível em: https://pimrj.org/index.php/pimrj/article/view/79.. Acesso em: 16 apr. 2026.