1. M.H. Norman, D.J. Minick and G.C. Rigdon, J. Med. Chem. 39 (1996) 149.
2. L.M. Lima, P. Castro, A.L. Machado, C.A.M. Fraga, C. Lugnier, V.L.G. de Moraesc and E.J. Barreiroa, Bioorg. Med. Chem. 10 (2002) 3067.
3. A. Raasch, O. Scharfestein, C. Trankle, U. Holzgrabe and K. Mohr, J. Med. Chem. 45 (2002) 3809.
4. T. Eicher, S. Hauptmann, The Chemistry of Heterocycles, Georg Thieme Verlag, New York, 1995
5. F.D. King, Medicinal Chemistry: Principles and Practice, Royal Society of Chemistry, Cambridge, England, 1994