| Number | Name | Date | Kind |
|---|---|---|---|
| 4837798 | Cohen et al. | Jun 1986 | |
| 5127047 | Bell et al. | Jun 1992 | |
| 5138653 | Le Clercq | Aug 1992 |
| Number | Date | Country |
|---|---|---|
| 5-37556 | Feb 1993 | JPX |
| 5327762 | Dec 1993 | JPX |
| Entry |
|---|
| Audio Messaging Interchange Specification (AMIS) Analog Protocol, Version 1 Issue 2 Feb. 1992. |
| "Methodology for Creating and Distributing Audio Messages" IBM Technical Disclosure Bulletin vol. 36 No. 09B Sep. 1993. |