Turkmen, Cafer, and Ali Sungur. “Influence of Humic Acid on Availability of Zn, Cu, Mn, Fe in Soils”. Asian Journal of Chemistry 26, no. 13 (June 26, 2014): 3977–3980. Accessed July 23, 2024. https://asianpubs.org/index.php/ajchem/article/view/26_14_47.