Abdualameer Jawad, S. “Synthesis and Characterization of Azo Amidazole Ligand Type N2 and Metal Complexes With Di Valence Cobalt , Nickel and Copper”. Al-Qadisiyah Journal of Pure Science, Vol. 22, no. 3, Jan. 2018, pp. 20 -34, https://journalsc.qu.edu.iq/index.php/JOPS/article/view/598.