Kametani,T. et al.
Journal of Medicinal Chemistry, 1969 , vol. 12, p. 694 - 696

Babayan, A. T.; Torosyan, G. O.; Gekchyan, G. G.; Mkrtchyan, R. S.; Tagmazyan, K. Ts.; Mushegyan, A. V.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 4 p. 380 - 383
Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 4 p. 475 - 478

Bumgardner,C.L.
Journal of the American Chemical Society, 1963 , vol. 85, p. 73 - 78