1. Cristofol, E., Rojas, F.S., & Pavon, J.M.C. (1991). Evaluation of various N- phenylthiosemicarbazones as chromogenic reagents in spectrophotometric analysis. Talanta, 38, 445–448.
2. Desai, M.J., & Desai, K.K. (1999). Spectrophotometric determination of copper(II) and iron(III) with 2,4-dihydroxy-5-bromoacetophenonethiosemicarbazone. Asian Journal of Chemistry, 11(4), 1313–1316.
3. Eichhorn, G.L. (1975) Inorganic biochemistry. New York: Elsevier Scientific Publishing Company.
4. Kocharekar, Archana, R., & Thakkar, N.V. (2004). Extractive Spectrophotometric determination of copper(II) and its applications in pharmaceutical samples and alloys. Journal of Scientific and Industrial Research, 63(3), 283–286.
5. Kudapali, Y.S., & Suresh, T. (2004). Spectrophotometric determination of copper(II) with 2,5-dihydroxyaceto- phenonebenzoic hydrozone. Oriental Journal of Chemistry, 20(2), 313–316.