1. Buj M., Filhol R.; US Patent No. 6,118,006; September 12, 2000; Assigned: Sanofi-Synthelabo, Paris, France
2. Main Brian G, Barlow Jeffrey J.; US Patent No. 4,143,140; March 6, 1979; Assigned to Imperial Chemical Industries Limited (London, GB2)
3. Merck Index 9871
4. Kleeman and Engel p. 951
5. I.N. p. 1018