| Number | Name | Date | Kind |
|---|---|---|---|
| 2968521 | Gross | Jan 1961 | |
| 3019074 | Leeser | Jan 1962 | |
| 3893028 | Febvre et al. | Jul 1975 | |
| 4362392 | Kumata | Dec 1982 | |
| 4542286 | Golarz | Sep 1985 | |
| 4603335 | Koyasu | Jul 1986 | |
| 4693329 | Hikita | Sep 1987 | |
| 4823080 | Lin | Apr 1989 |
| Entry |
|---|
| "Model 2300 Elapsed Time Recorder," Star Systems Incorporated, Houston, Texas, Instruction Leaflet. |
| PIX-10 Electronic Time Recorder, Operation Manual, Amano Cincinnati Inc., 4 pgs., 1993. |
| PIX-3000 Series, Electronic Time Recorder, Operation Manual, Amano Cincinnati Inc., pp. 1-22. |
| Centennial Installation, Operating and Programming Instructions, Simplex Time Recorder Co., pp. 1-20, 1988. |