Pesin, V. G.; Sergeev, V. A.; Ostashkova-Kul'kova, N. V.
Journal of Organic Chemistry USSR (English Translation), 1989 , vol. 25, # 8.2 p. 1626 - 1628
Zhurnal Organicheskoi Khimii, 1989 , vol. 25, # 8 p. 1799 - 1801

Sergeev,V.A.; Pesin,V.G.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1971 , vol. 7, p. 561 - 562
Khimiya Geterotsiklicheskikh Soedinenii, 1971 , vol. 7, # 5 p. 601 - 602