Three Duets, G-major, F-major and A-major, KV 301,302,305, for violin and viola
based on the sonatas for piano and violin KV301, KV302 and KV305 KV301 (Son. in G major), KV302 (Son. in E-flat major), KV305 (Son. in A major). http://music4viola.info/work-info/35/Mozart%20W.a./three-duets-g-major-f-major-and-a-major-kv-301-302-305-for-violin-and-viola