1. 3GPP, 3G TS 26.090: “AMR Speech Codec; Transcoding function”
2. 3GPP, 3G TS 26.093: “AMR Speech Codec; Source Controlled Rate operation”
3. 3GPP, 3G TS 26.094: “AMR Speech Codec; Voice Activity Detector for AMR Speech Traffic Channels”
4. 3GPP, 3G TS 26.092: “AMR Speech Codec; comfort noise for AMR Speech Traffic Channels”
5. 3GPP, 3G TS 26.091: “AMR Speech Codec; Error Concealment of Lost Frames”