ISLAM, K.M.S.; SCHUMACHER, A.; GROPP, J.M. Humic Acid Substances in Animal Agriculture. Pakistan Journal of Nutrition, [S. l.], v. 4, n. 3, p. 126–134, 2005. DOI: 10.3923/pjn.2005.126.134. Disponível em: https://pjnonline.org/pjn/article/view/229. Acesso em: 1 jul. 2025.