Data retrieval based on the smart contract within the blockchain. Periodicals of Engineering and Natural Sciences, [S. l.], v. 9, n. 4, p. 491–507, 2021. DOI: 10.21533/pen.v9.i4.959. Disponível em: https://pen.ius.edu.ba/index.php/pen/article/view/959. Acesso em: 2 jun. 2026.