| S. No. | Patent identifier |
|---|---|
| 1 | US5032592A |
| 2 | EP0154528B1 |
| 3 | US5741938A |
| 4 | EP0154528A2 |
| 5 | EP0961764A1 |
| 6 | US8041455B2 |
| 7 | US4845119A |
| 8 | US6720439B1 |
| 9 | US5084478A |
| 10 | WO1998037048A1 |
| 11 | EP0193303A2 |
| 12 | EP2386535B1 |
| 13 | US4873329A |
| 14 | US5236953A |
| 15 | US8383863B2 |
| 16 | US20110282102A1 |
| 17 | EP2386535A1 |
| 18 | EP0193303B1 |
