Easton, Christopher J.; Ivory, Andrew J.; Smith, Craig A.
Journal of the Chemical Society. Perkin Transactions 2, 1997 , # 3 p. 503 - 507

Ogawa, Toshihisa; Nakazato, Atsuro; Sato, Masakazu; Hatayama, Katsuo
Synthesis, 1990 , # 6 p. 459 - 460