| Number | Name | Date | Kind |
|---|---|---|---|
| 4097923 | Eckert, Jr. et al. | Jun 1978 | |
| 4122532 | Dlugos et al. | Oct 1978 | |
| 4511793 | Racanelli | Apr 1985 | |
| 4649266 | Eckert | Mar 1987 | |
| 4713761 | Sharpe et al. | Dec 1987 | |
| 4752950 | Le Carpentier | Jun 1988 | |
| 4800504 | Durst, Jr. et al. | Jan 1989 | |
| 4800505 | Axelrod et al. | Jan 1989 | |
| 4812965 | Taylor | Mar 1989 | |
| 4813912 | Chickneas et al. | Mar 1989 | |
| 4831555 | Sansone et al. | May 1989 | |
| 4852013 | Durst, Jr. et al. | Jul 1989 |
| Entry |
|---|
| "Shiptrac'r Applications" by Vocam Systems Inc., Bloomington, Minnesota; copyright 1988. |