Music Reference and Tutorials
Music thesaurus
Music reference
Eastman School Bibliography from the 1970s, music books recommended for composers -- aesthetics, orchestration, essays, biography, survey, theory; and a few books for horn players
About horn playing
New Chamber Music for Horn, annotated list of solos, duos with another instrument, trios, etc
Free Improvisation and the Horn (article)
Other horn resources
Cornucopia: the Book, compendium of articles from thepast 20 years of the Cornucopia newsletter for New England horn players, Marilyn Kloss, editor
Horn Etudes Catalog by Ricardo Matosinhos, in Portuguese and English