http://stevenestrella.com/composers/composerfiles/heller1888.html Biographical data, recommended CDs, books and sheet music, bibliography, and links to biographical essays from Dr. Estrella's Incredibly Abridged Dictionary of Composers. http://www.karadar.net/Dictionary/heller.html Brief profile and mp3 sample of his work. From Karadar Classical Music. http://www.hnh.com/composer/heller.htm Brief profile and description of works from Naxos.