Bougrin, Khalid; Bennani, A. Kella; Tetouani, Souad Fkih; Soufiaoui, Mohamed
Tetrahedron Letters, 1994 , vol. 35, # 45 p. 8373 - 8376

Risitano, Francesco; Grassi, Giovanni; Foti, Francesco
Tetrahedron Letters, 1983 , vol. 24, # 52 p. 5893 - 5896