Costisella, Burkhard; Ozegowski, Sigrid; Gross, Hans
Phosphorus, Sulfur and Silicon and the Related Elements, 1994 , vol. 86, # 1-4 p. 169 - 176

Bulpin, Andrew; Masson, Serge; Sene, Aboubacary
Tetrahedron Letters, 1989 , vol. 30, # 26 p. 3415 - 3418