Kozhevnikov; Kovalev; Rusinov; Chupakhin; Aleksandrov
Russian Journal of Organic Chemistry, 2002 , vol. 38, # 5 p. 744 - 750

Shkurko, O. P.; Gogin, L. L.; Baram, S. G.; Mamaev, V. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1987 , vol. 23, # 2 p. 216 - 221
Khimiya Geterotsiklicheskikh Soedinenii, 1987 , vol. 23, # 2 p. 257 - 262