Tetrahedron Letters, , vol. 47, # 22 p. 3693 - 3696

Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), , vol. 40, # 6.2 p. 1257 - 1262
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, , # 6 p. 1417 - 1422

Trofimov, B.A.; Korostova, S.E.; Mikhaleva, A.I.; Sobenina, L.N.; Vasil'ev, A.N.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1982 , vol. 18, # 12 p. 1257 - 1265
Khimiya Geterotsiklicheskikh Soedinenii, 1982 , vol. 18, # 12 p. 1631 - 1639