1. Telecom. Standardization Sector of ITU, Video coding for low bitrate communication. ITU-T Recommendation H.261 (1990)
2. ISO/IEC, Information technology — generic coding of moving pictures and associated audio information: Video (MPEG-2) International Standard 13818-2:2000 (1996)
3. Telecom. Standardization Sector of ITU, Video coding for low bitrate communication ITU-T Recommendation H.263 (March 1996)
4. Telecom. Video coding for low bitrate communication, ITU-TRecommendation H.263 Version 2 (February 1998)
5. ISO/IEC, Information technology — coding of audio-visual objects part 2: Visual (MPEG-4), JTC1/SC29/WG11 N4350, International Standard 14496-2 (July 2001)