HASSAN, M. Y.; KHALIFA, O. O.; TALIB, A. A.; ABDULLA, A. H. Unconstrained Facial Recognition Systems: A Review. Asian Journal of Applied Sciences, [S. l.], v. 3, n. 2, 2015. Disponível em: https://ajouronline.com/index.php/AJAS/article/view/2151. Acesso em: 3 jul. 2022.