Shikhaliev, Kh. S.; Shmyreva, Zh. V.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1988 , vol. 24, # 8 p. 898 - 900
Khimiya Geterotsiklicheskikh Soedinenii, 1988 , # 8 p. 1091 - 1093