Izvornik: Six Duos, Op. 9. Six Duos, Op. 9 composed by Felix-Jean Prot. In the keys of E-flat, C, G, A, D, F. Classical. For 2 violas.
Prijevod: Šest Duos, op. 9. Šest Duos, op. 9 sastoji Felix-Jean Prot. Viola note. Uredio Kenneth Martinson. Za 2 viole. Ovo izdanje. Level 5.