1. Encyclopedia of Chemical Technology,1996
2. Gosser, L. W, and, Schwartz, J. T, U.S. Patent 4832938, 1989.
3. Gosser, L. W, and, Schwartz, J. T, U.S. Patent 4772458, 1988.
4. Gosser, L. W, and, Paoli, M. A, U.S. Patent 5135731, 1992.
5. Kawakami, M, Ishiuchi, Y, Nagashima, H, Tomita, T, and, Hiramatsu, Y, U.S. Patent 5399334, 1995.