Numan, A. .T., K. .M. Sultan, and A.S. Abdullah. 2017. “Complexeation Behavior of CoII, NiII, CuII, ZnII, and CdII Ions Toward Schiff Base Derived From 2, 4 -Dihydroxy Benzaldehyde and O-Phenylene Diamine”. Ibn AL-Haitham Journal For Pure and Applied Sciences 22 (3). https://www.jih.uobaghdad.edu.iq/index.php/j/article/view/1171.