O. Agrawal, K. Verma, S. Khatkar, and R. Kumar Malik, “Amperometric Trace Determination of Cu(II), Ag(I), Au(III), Pd(II) and Pt(IV) with 2-Mercapto and 3-Mercaptoprpanoic acids”, ajc, vol. 6, no. 4, pp. 911–916, Mar. 2010.