| Number | Date | Country | Kind |
|---|---|---|---|
| 55/62458 | May 1980 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3805026 | Anders | Apr 1974 | |
| 4021777 | Shepard | May 1977 | |
| 4092524 | Moreno | May 1978 | |
| 4270043 | Baxter et al. | May 1981 | |
| 4283769 | Asada | Aug 1981 | |
| 4323771 | Chalker, Jr. et al. | Apr 1982 | |
| 4333085 | Witts | Jun 1982 |
| Entry |
|---|
| E. Fabo & E. Hoglund, "CTR-Computerized Time Recording", Ericsson Review No. 2, 1980. |