http://stevenestrella.com/composers/composerfiles/castillo1966.html Biographical data, recommended CDs, books and sheet music, bibliography, and link to biographical essay from Dr. Estrella's Incredibly Abridged Dictionary of Composers. http://web02.hnh.com/composer/btm.asp?fullname=Castillo,%20Ricardo Biographical sketch and recommened Naxos recordings. http://www.karadar.net/Dictionary/castillo.html Musica Classica Classical Music Dictionary entry with life and comments on style.