ERVIÖ, R.; MÄKITIE, O. Studies on the effect of clay and organic matter contents on the determination of cation exchange properties in clay soils by the ammonium acetate and methylene-blue methods. Agricultural and Food Science, [S. l.], v. 41, n. 2, p. 73–81, 1969. DOI: 10.23986/afsci.71727. Disponível em: https://journal.fi/afs/article/view/71727. Acesso em: 20 may. 2024.