Taylor, Edward C.; Macor, John E.
Journal of Heterocyclic Chemistry, 1985 , vol. 22, p. 409 - 411

Lobanov, P. S.; Grebelkin, A. L.; Zaitsev, D. I.; Gindin, V. A.; Potekhin, A. A.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1991 , vol. 27, # 10 p. 1116 - 1119
Khimiya Geterotsiklicheskikh Soedinenii, 1991 , vol. 27, # 10 p. 1388 - 1391