OKORONKWO, N.; ODEMELAM, S.; ANO, O. Levels of toxic elements in soils of abandoned waste dump site. African Journal of Biotechnology, [S. l.], v. 5, n. 13, 2009. DOI: 10.4314/ajb.v5i13.43089. Disponível em: https://www.ajol.info/index.php/ajb/article/view/43089. Acesso em: 9 nov. 2026.