Vasudeva Reddy, K., et al. “Spectrophotometric Determination of Copper(II) in Biological Samples by Using 2-Acetylfuran Thiosemicarbazone As Chelating Reagent”. Asian Journal of Chemistry, vol. 23, no. 10, Aug. 2011, pp. 4425-9, https://asianpubs.org/index.php/ajchem/article/view/10869.