U.S. Opera Information about American opera composers and their works. http://www.hapka.com/usopera

OperaGlass: Opera Composers Alphabetical listing with works and links to better-known composers with details of certain compositions. From Stanford University. http://rick.stanford.edu/opera/composers/

AZOpera Composer Biographies Arizona Opera provides background, life, and musical details for many of those whose works they have performed. http://www.azopera.com/learn/composer/

Puccini's La Boheme Libretto Complete English translation of the opera with each act listed separately, aria translations, synopsis, plus the composer's thoughts upon completion and a list of choruses and protagonists. http://www.bohemianopera.com/bohemelibretto.htm