S. Raditladi, Zukiswa, et al. “The Impact of EDTA and Sodium Hexametaphosphate Habit Modifiers in the Production of Quality Soda Ash Crystals”. Asian Journal of Chemistry, vol. 16, no. 3, June 2016, pp. 1618-24, https://asianpubs.org/index.php/ajchem/article/view/14394.