1. 1. Y. Tashiro, K. Nagashima, S. Aoki, and Y. Aboshi, Japan Patent, 1980, 045616.
2. 2. Y. Tashiro, T. Nagashima, S. Aoki, and R. Nishizawa, Japan Patent, 1978, 119844.
3. 3. H. Nohira and K. Ueda, Japan Patent, 1982, 193448.
4. 4. H. Nohira, Japan Patent, 1984, 051239.
5. 5. SAPI91, H.-F. Fan, 1991, Rigaku Corporation, Tokyo, Japan.