1. Akhtar, S., Sharkery, A. G., Jr., Shultz, J. L., and Yavorsky, P. U. (1974). Am. Chem. Soc., 167th Natl. Meet., Los Angeles, Calif.
2. ASTM (1973). 1973 Annual Book of ASTM Standards. Part 19: 380. Philadelphia, Pennsylvania.
3. Ashworth, M. R. F. (1972). The Determination of Sulphur-Containing Groups. Vol. I: Sulfoxides Sulfones.
4. Ashworth, M. R. F. (1976). The Determination of Sulphur-Containing Groups. Vol. II: Thiols.