A Review on Real Time Heart Rate Monitoring System using USB camera. International Journal of Engineering and Computer Science, india, v. 9, n. 2, p. 24934–24939, 2020. DOI: 10.18535/ijecs/v9i2.4434. Disponível em: http://www.ijecs.in/index.php/ijecs/article/view/4434. Acesso em: 5 dec. 2025.