| Number | Name | Date | Kind |
|---|---|---|---|
| 4631601 | Brugliera et al. | Dec 1986 | |
| 4977455 | Young | Dec 1990 | |
| 5046093 | Wachob | Sep 1991 |
| Entry |
|---|
| "Interactive Videodisc Systems for Education", J. Bennion, E. Schneider, Journal of the Society of Motion Picture and Television Engineers, vol. 84, No. 12, Dec. 1975. |
| Cable data advertisement, Cablevision, Feb. 9, 1981. |
| DAP II advertisement, Nov.-Dec. 1981. |