GUO, Jianyu. Graded Cybersecurity Protection: Practices and Challenges in System Implementation. International Journal of Advance in Applied Science Research, [S. l.], v. 4, n. 12, p. 22–27, 2025. Disponível em: https://h-tsp.com/index.php/ijaasr/article/view/203. Acesso em: 16 jan. 2026.