1. ITU-T Z.104: Encoding of SDL data. International Telecommunication Union (2004)
2. Schröder, R., Böhme, H., von Löwis, M.: SDL Integrated Tool Environment. Web site, Humboldt-Universität zu Berlin (1997-2003),
http://www.informatik.hu-berlin.de/SITE/
3. ITU-T Z.100: Specification and Description Language (SDL). International Telecommunication Union (1996)
4. ITU-T X.208: Specification of Abstract Syntax Notation One (ASN.1). International Telecommunication Union (1988)
5. ITU-T Z.105: SDL combined with ASN.1 modules. International Telecommunication Union (2003)