| Number | Name | Date | Kind |
|---|---|---|---|
| 6061721 | Ismael et al. | May 2000 | A |
| 6230160 | Chan et al. | May 2001 | B1 |
| 6321261 | Glass | Nov 2001 | B1 |
| 6425017 | Dievendorff et al. | Jul 2002 | B1 |
| Entry |
|---|
| Gamma Erich “Design Patterns Elements of Reusable Object-Oriented Software” Addison-Wesley 1995 p. 223-232. |