Guitarbands: Opal Short introduction and discography. http://guitarbands.de/opal.htm

All Music Guide: Opal Biography of the duo, and a discography with reviews. http://www.allmusic.com/cg/amg.dll?p=amg&sql=B97xvadskv8w5

Boogie Down with Trevor Provides a biography and photo galleries http://www.geocities.com/boogiedownwithtrevor/Trevorwelcome.html