Yang, Jie, et al. “Study on the Separation and Determination of Palladium, Platinum and Rhodium by Solid Phase Extraction and Ultra Performance Liquid Chromatography”. Asian Journal of Chemistry, vol. 23, no. 11, Sept. 2011, pp. 4815-8, https://asianpubs.org/index.php/ajchem/article/view/10989.