A. Anarbayev, Abibula, et al. “Solubility in Quaternary Systems FeCl2-H3PO4-H2O and ZnCl2-H3PO4-H2O”. Asian Journal of Chemistry, vol. 24, no. 10, May 2012, pp. 4309-12, https://asianpubs.org/index.php/ajchem/article/view/9643.