| Number | Name | Date | Kind |
|---|---|---|---|
| 5309355 | Lockwood | May 1994 | |
| 5319542 | King et al. | Jun 1994 | |
| 5469206 | Strubbe et al. | Nov 1995 | |
| 5630125 | Zellweger | May 1997 | |
| 5710887 | Chelliah et al. | Jan 1998 |
| Entry |
|---|
| Database Systems Concepts, Henry F. Korth, Abraham Silberschatz, 2nd ed, 1991. |