Panigrahi, G. P.; Sinha, T. K.
Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry, 1983 , vol. 22, # 10 p. 1065 - 1067
Sultanov, A. V.; Savvin, S. B.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1988 , vol. 24, p. 106 - 109
Khimiya Geterotsiklicheskikh Soedinenii, 1988 , vol. 24, # 1 p. 126 - 130