Serbetci, Z., and C. Alkan. “Spectroscopic Studies of 1,10-Phenanthroline-5,6-[4,4’-(ethane-1,2- diilbis(oxy))dibenzenamine] and Its Transition Metal Complexes”. Asian Journal of Chemistry, vol. 22, no. 2, Mar. 2010, pp. 1087-90, https://asianpubs.org/index.php/ajchem/article/view/11231.