Narayana, B., et al. “Complexo-Titrimetric Determination of Palladium(II) Using 1,3,4,6-Tetrahydropyrimimdine-2-Thione As a Replacing Reagent ”. Asian Journal of Chemistry, vol. 5, no. 1, Mar. 2010, pp. 29-34, https://asianpubs.org/index.php/ajchem/article/view/24746.