Zheng, H.L., W. Fan, W.Y. Xie, F.Y. Ji, M.Z. Tan, and C. Yang. “Catalytic Spectrophotometric Determination of Ultra Trace-Level Copper(II) With Indigo Carmine”. Asian Journal of Chemistry 25, no. 17 (November 11, 2013): 9547–9550. Accessed November 24, 2024. https://asianpubs.org/index.php/ajchem/article/view/25_18_28.