Originalus: 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.
Vertimas: Šeši Duos, op. 9. Šeši Duos, op. 9 sudaro Felix-Jean Prot. Viola natos. Redagavo Kenneth Martinson. 2 altus. Tai leidimas. 5 lygis.