This is the bible at the University of Southern California. Contains everything from flexibility, to characteristic studies.
"Oscar Franz (1843-1886) was one of the most prominent teachers and performers of the horn in the late nineteenth century. Franz spent most of his career in Dresden, where he taught at the Dresden Conservatory and performed Principal Horn in the court orchestra. Franz was well respected in his time, and it is to him that Richard Strauss (1864-1949) dedicated the orchestral score of his Horn Concerto No. 1, Op. 11 (1883).
Oscar Franz wrote a number of teaching materials for the horn. His Grosse theoretisch-practische Waldhorn-Schule [Complete Theoretical and Practical Horn Method] was first published around 1880. In this method Franz put forth many of his ideas for performing on the horn, which I cover in more depth in an article in Horn Articles Online:
-- John Ericson (hornmatters.com)
With Standard notation.