SMARANDACHE, F.; AKULA, S.; ALZAHRANI, S. I.; ARSLAN, F.; IJAZ, A. PPG-Based Sleep Stage Classification Using Pulse Wave Feature Fusion and Explainable AI. Engineering, Technology & Applied Science Research, Greece, v. 15, n. 5, p. 27640–27645, 2025. DOI: 10.48084/etasr.13077. Disponível em: https://mail.etasr.com/index.php/ETASR/article/view/13077. Acesso em: 19 may. 2026.