| Number | Date | Country | Kind | 
|---|---|---|---|
| 1-342695 | Dec 1989 | JPX | |
| 2-185867 | Jul 1990 | JPX | 
| Number | Name | Date | Kind | 
|---|---|---|---|
| 4981950 | Masaki et al. | Jan 1991 | 
| Number | Date | Country | 
|---|---|---|
| 0127899 | Dec 1984 | EPX | 
| 0135722 | Apr 1985 | EPX | 
| Entry | 
|---|
| Stedman's Medical Dictionary, 25th Edition, pp. 1433-1434, Williams and Wilkins, Baltimore (1990). |