1. ITU-T Rec. H.261. Video codec for audiovisual services at p × 64kbit/s. 1993.
2. ISO/IEC IS 11172-2. Information technology—Coding of moving pictures and associated audio for digital storage media up to about 1.5Mbits/s—Part 2: Video. 1993.
3. ITU-T Rec. H.262|ISO/IEC 13818-2. Information technology—Generic coding of moving pictures and associated audio information—Video. 2000.
4. ITU-T Rec. H.263. Video coding for low bit rate communication. 2001.
5. ISO/IEC 14496-2. Information technology—Coding of audio-visual objects—Part 2: Visual. 2004.