Mahdi, Alyaa Esam. 2013. “Spectral Study of Pt (II), Cr (II) Polymeric Complexes of the Ligand N- Crotonyl -2- Hydroxy-Phenylazomethine”. Al-Khwarizmi Engineering Journal 9 (4): 39-45. https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/183.