Caron; Brassard
Tetrahedron, 1993 , vol. 49, # 4 p. 771 - 784

Rao, B. Kesava; Hanumaiah, T.; Rao, J. U. M.; Rao, K. V. J.; Thomson, Ronald H.
Phytochemistry (Elsevier), 1984 , vol. 23, # 9 p. 2104 - 2105