Liu, Hai-Xing, et al. “Synthesis and Crystal Structure of Tris-(1,10-Phenanthroline)-Iron(II) Dichromate Tetrahydrate, Fe(C12H8N2)3Cr2O7·4H2O”. Asian Journal of Chemistry, vol. 25, no. 6, Jan. 2013, pp. 3515-6, doi:10.14233/ajchem.2013.13747.