Sonate à quatre mains pour le forte-piano, Opus 6. Early edition. Bonn: Simrock [1798].In bound collection containing first and early editions of Opus 6 (Simrock), Opus 10 (f.e.), Opus 49 (Bureau d’arts), Opus 31, nos. 1-2, Opus 22 (f.e.), Opus 27, no. 1 (f.e.), Opus 7 (f.e.), Opus 33 (f.e.), and Opus 43, piano arr. (f.e.), with ownership inscription of Prince Ferdinand Kinsky (”Fr. K.” and later ownership inscription “E. Kinsky” (”E.K.”)