TETRAHEDRON, vol. 52, no. 2, page. 571 - 588, 1996-01-08
TETRAHEDRON LETTERS, vol. 36, no. 19, page. 3361 - 3364, 1995-05-08
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, vol. 115, no. 16, page. 7472 - 7477, 1993-08-11