Blockchain-based secure tender management system: a smart contract framework for transparent and fair E-procurement. Natural and Applied Sciences International Journal (NASIJ), Peshawar, Pakistan, v. 6, n. 1, p. 87–100, 2025. Disponível em: https://www.ideapublishers.org/index.php/nasij/article/view/6.1.5. Acesso em: 23 jul. 2026.