TETRAHEDRON LETTERS, vol. 47, no. 24, page. 4037 - 4039, 2006-06-06
TETRAHEDRON LETTERS, vol. 46, no. 9, page. 1475 - 1477, 2005-02-28
TETRAHEDRON LETTERS, vol. 45, no. 18, page. 3543 - 3546, 2004-04-26