Nurkenov, O., I. Kulakov, Z. Satpaeva, A. Zhakina, and KaluginС. “Synthesis and Intramolecular Geterocyclezation of Thiosemycarbozide Derivatives on the Basis Salicylic Acid”. Chemical Bulletin of Kazakh National University, Vol. 61, no. 1, Mar. 2011, pp. 322-8, https://bulletin.chemistry.kz/index.php/kaznu/article/view/930.