V. Nair, Sheena. “Oxidation of Binary Mixtures of 1,3-Dialkylthiourea and Thiourea: Formation of 3-Amino-4-Alkyl-5-Alkylimino-Δ2-1,2,4-Thiadiazolines ”. Asian Journal of Chemistry, vol. 15, no. 2, Mar. 2010, pp. 1075-80, https://asianpubs.org/index.php/ajchem/article/view/21749.