Donahue, Gary A. (2007). Network Warrior (1st ed.). O'Reilly Media, Inc. p. 233. ISBN 9780596101510. OCLC 865092442. 9780596101510 ↩
"Flex links in 7600" (PDF). http://www.cisco.com/en/US/docs/routers/7600/ios/12.2SXF/configuration/guide/flexlink.pdf ↩