EKPO, Timothy. Man and the study of the soil: In Asuquo, Essien, B. O. and Ekpo, T. U. (eds), Man and Ecology. Uyo MEFNigeria Limited. Afrischolar Discovery Repository (Annex), [S. l.], p. 183–194, 2000. DOI: 10.60951/afrischolar-497. Disponível em: https://www.publications.afrischolar.net/index.php/home/article/view/497. Acesso em: 21 mar. 2026.