CEN/CENELEC The Joint European Standards Institution. Information technology - Functional standard for profile A/MH21 Message handling systems - IPMS-IPM-UA to IPM-UA ENV bbbb: Working Draft Functional Standard A/MH21 Version 1.0 July 1992.
Παραπομπή σε μορφή Chicago (17η εκδ.)CEN/CENELEC The Joint European Standards Institution. Information Technology - Functional Standard for Profile A/MH21 Message Handling Systems - IPMS-IPM-UA to IPM-UA ENV Bbbb: Working Draft Functional Standard A/MH21 Version 1.0 July 1992.
Παραπομπή σε μορφή MLA (8th εκδ.)CEN/CENELEC The Joint European Standards Institution. Information Technology - Functional Standard for Profile A/MH21 Message Handling Systems - IPMS-IPM-UA to IPM-UA ENV Bbbb: Working Draft Functional Standard A/MH21 Version 1.0 July 1992.
