1. “United States Pharmacopeia,” 18th Ed.,1910
2. H. Ruschig, W. Aumuller, G. Korger, H. Wagner, J. Scholz, and A. Bänder, U.S. Patent 2,968,158, January 17, 1961 (assigned to The Upjohn Co.)
3. The Merck Index 8th Edition,1968
4. L.M. Humphrey, The Upjohn Co., unpublished data
5. Crystallographic Data. 173. Tolbutamide