Nagao,Y. et al.
Tetrahedron Letters, 1977 , p. 1345 - 1348

Khurana, Jitender M.; Kandpal, Bhaskar M.; Chauhan, Yogendra K.
Phosphorus, Sulfur and Silicon and the Related Elements, 2003 , vol. 178, # 6 p. 1369 - 1375

Engman; Persson
Synthetic Communications, 1993 , vol. 23, # 4 p. 445 - 458