Kolos, N. N.; Nikishin, D. I.; Chechina, N. V.; Zamigaylo, L. L. Synthesis of Pyrimidine-2,4,6-Trion and 2-Thioxo-Pyrimidin-4,6-Dione With Imidazolidine Fragment. Khark. Univ. Bull. Chem. Ser. 2013, 45-52.