FORGHA, N. G.; MBELLA, M. E.; NGANGNCHI, F. H. International Journal of Sciences: Basic and Applied Research (IJSBAR), [S. l.], v. 21, n. 1, p. 287–303, 2015. Disponível em: https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/3517. Acesso em: 3 jul. 2024.