| Number | Name | Date | Kind |
|---|---|---|---|
| 948817 | Lewis | Feb 1910 | A |
| 3221172 | Rolison | Nov 1965 | A |
| 3609426 | Gaul | Sep 1971 | A |
| 3622840 | Kahn | Nov 1971 | A |
| 3861485 | Busch | Jan 1975 | A |
| 4800311 | Weldon et al. | Jan 1989 | A |
| Entry |
|---|
| Sears et al., University Physics, Addition-Wesley Publishing Company, Sixth edition, pp. 349-350. |