A. K.  Sanki, Bhattacharya, R., Atta, A. Kumar, Suresh, C. G., and Pathak, T., ?Diastereoselective addition of planar N-heterocycles to vinyl sulfone-modified carbohydrates: a new route to isonucleosides?, Tetrahedron, vol. 64, no. 45, pp. 10406-10416, 2008.