TETRAHEDRON LETTERS, vol. 39, no. 49, page. 9039 - 9042, 1998-12-03
TETRAHEDRON LETTERS, vol. 39, no. 15, page. 2163 - 2166, 1998-04-09
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, vol. 8, no. 12, page. 1503 - 1506, 1998-01