JOURNAL OF HETEROCYCLIC CHEMISTRY, vol. 30, no. 3, page. 825 - 827, 1993-05
TETRAHEDRON LETTERS, vol. 33, no. 44, page. 6661 - 6664, 1992-10-27
JOURNAL OF ORGANIC CHEMISTRY, vol. 57, no. 19, page. 5065 - 5066, 1992-09-11
SYNLETT, no. 4, page. 306 - 308, 1992-04
TETRAHEDRON LETTERS, vol. 33, no. 4, page. 507 - 510, 1992-01-21