1. Toeplitz, B., The Squibb Institute, Personal communication.
2. Funke, P.T. & Puar, M.S., The Squibb Institute Personal communication.
3. Whigan, D., The Squibb Institute, Personal communication.
4. Anon, U.S. Pharmacopeia XIX, p.530(1975).
5. Papastephanou, C., The Squibb Institute, Unpublished data.