A. S. Gotsulia, P. S. Knyazevich, O. I. Panasenko, and Y. G. Knysh, “Synthesis and physical-chemical research of 7-((3-thio-4-r-4h-1,2,4-triazole-5-yl)methyl)theophylline carbonyl derivatives”, Zaporozhye Medical Journal, vol. 17, no. 3, Jun. 2015.