http://www.byu.edu/~hurlbut/fmddp/adam-h.html Extensive bibliography from the French Medieval Drama Database Project. http://www.britannica.com/eb/article?eu=3679 Brief profile from Britannica.com. http://www.karadar.net/Dictionary/halle.html Very brief profile. http://stevenestrella.com/composers/composerfiles/halle1287.html Biographical data, recommended CDs, books and sheet music, bibliography, and links to biographical essays from Dr. Estrella's Incredibly Abridged Dictionary of Composers.