SIRAPPA, M. P.; TANDISAU, P. Ascertainment of K Nutrient Availability Class for Maize by Several Methods. JOURNAL OF TROPICAL SOILS, [S. l.], v. 20, n. 1, p. 21–27, 2016. DOI: 10.5400/jts.2015.v20i1.21-27. Disponível em: https://journal.unila.ac.id/index.php/tropicalsoil/article/view/217. Acesso em: 5 aug. 2025.