1. American National Standards Institute (ANSI) Digital Hierarchy-Electrical Interfaces 1993
2. American National Standards Institute (ANSI) A technical report on synchronization network management using synchronization status messages 1994
3. American National Standards Institute (ANSI) Telecommunications-Digital hierarchy - Format specifications 1995a
4. American National Standards Institute (ANSI) Telecommunications-Synchronous Optical Network (SONET) - Basic Description including Multiplex Structure, Rates, and Formats 1995b
5. American National Standards Institute (ANSI) Telecommunications -Synchronous Optical Network (SONET) - Jitter at Network Interfaces - DS1 Supplement 1995c