E. N. Mezaal, K. A. Sadiq, A. N. Zaki, and R. M. Rumez, “Spectrophotometric Determination of Cu(II) by Complex with Ethyl Cyano(2-Methyl Carboxylate Phenyl Azo Acetate) (ECA)”, IHJPAS, vol. 30, no. 1, pp. 96–106, Jun. 2017, doi: 10.30526/30.1.1063.