Savel'ev, V. L.; Makarov, A. V.; Zagorevskii, V. A.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , vol. 19, # 6 p. 686
Khimiya Geterotsiklicheskikh Soedinenii, 1983 , vol. 19, # 6 p. 845
Hawkins, David G.; Meth-Cohn, Otto
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1983 , p. 2077 - 2087