Daukshas, V. K.; Martinkus, R. S.; Gineitite, V. L.; Urbonene, S. L.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1982 , vol. 18, # 9 p. 932 - 937
Khimiya Geterotsiklicheskikh Soedinenii, 1982 , # 9 p. 1215 - 1219

Partsvaniya, D. A.; Akhvlediani, R. N.; Zhigachev, V. E.; Gordeev, E. N.; Kuleshova, L. N.; Suvorov, N. N.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1986 , vol. 22, # 12 p. 1311 - 1315
Khimiya Geterotsiklicheskikh Soedinenii, 1986 , vol. 22, # 12 p. 1624 - 1628