| Number | Name | Date | Kind |
|---|---|---|---|
| 3022189 | Malmquist | Feb 1962 | A |
| 3713936 | Ramsay | Jan 1973 | A |
| 4325469 | Gurian | Apr 1982 | A |
| 5382461 | Wu | Jan 1995 | A |
| Number | Date | Country |
|---|---|---|
| 30 11 123 | Oct 1981 | DE |
| 0 305 207 | Mar 1989 | EP |
| 1 408 917 | Oct 1975 | GB |
| 1 536 421 | Dec 1978 | GB |
| 2 243 288 | Oct 1991 | GB |
| 46-41835 | Dec 1971 | JP |
| Entry |
|---|
| Database wpi section ch, week 199151 Derwent Publications Ltd, London, GB; XP002171061 & JP 03 249283 A (Achilles Corp) Nov. 7, 1991 abstract. |
| Database wpi section ch, week 199113 Derwent Publications Ltd, London, GB; Class A14, an 1991-092185 XP002171062 & JP 03 038340 A (two & one KK), Feb. 19, 1991 abstract. |
| European Patent Office; international search report for PCT/US 01/05370; dated Jul. 20, 2001. Not a Reference. |