VODYANITSKII, Y. Determination of the ratio hematite/goethite by soil color. The Journal of Nature Studies - Annals of Agrarian Science, [S. l.], v. 17, n. 2, 2019. Disponível em: https://mail.journals.org.ge/index.php/aans/article/view/339. Acesso em: 8 oct. 2025.