Sonata for Piano and Viola in E-flat Major, Op. 5, No. 3 With Marked and Unmarked String Parts (ed. Ernst Herttrich; piano fing. Klaus Schilde; viola fing. Tabea Zimmermann) Henle Music Folios
Johann Nepomuk Hummel (1778-1837) was one of the most respected pianists in his day, and was also a composer with quite some influence on later generations.