“The Electronic Transition Behavior Cr (III), Fe (III), Fe (II) and Ni (II), Transition Metal Cations In Ammonium Alum-Urea Room Temperature Ionic Liquid”, ANJS, vol. 16, no. 3, pp. 46–55, Sep. 2013, Accessed: May 02, 2024. [Online]. Available: https://anjs.edu.iq/index.php/anjs/article/view/576