1. CCITT Rec F.400 (1988) Message handling and directory service: operations and definition of service. CCITT Blue Book, Fascicle VIII.4
2. CCITT Rec H.261 (1990) Draft revision of recommendation H.261: video codec for audiovisual services at p×64 Kbit/s. Signal processing: image communication, pp 221–139
3. CCITT Rec. T.4 (1988) Standardization of Group 3 facsimile apparatus for document transmission. CCITT Blue Book, Fascicle VII.3
4. CCITT Rec T.411-Rec T.418 (1988) Open document architecture (ODA) and interchange format. CCITT Blue Book, Fascicle VII.6
5. CCITT Rec X.200 (1988) Data communication networks: open systems interconnection (OSI). CCITT Blue Book, Fascicle VIII.4