Ramsh, S. M.; Solov'eva, S. Yu.; Ginak, A. I.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , vol. 19, # 6 p. 611 - 614
Khimiya Geterotsiklicheskikh Soedinenii, 1983 , vol. 19, # 6 p. 764 - 768