Skornicka, J. E., & Boltz, E. G. (1939). Eb or BBb Bass (Tuba): A follow up course for individual or like-instrument class instruction / J.E.Skornicka and E.G. Boltz. Rubank.

Skornicka, Joseph E., and E. G. Boltz. Eb or BBb Bass (Tuba): A Follow Up Course for Individual or Like-instrument Class Instruction / J.E.Skornicka and E.G. Boltz. Miami, Fl.: Rubank, 1939.

Skornicka, Joseph E., and E. G. Boltz. Eb or BBb Bass (Tuba): A Follow Up Course for Individual or Like-instrument Class Instruction / J.E.Skornicka and E.G. Boltz. Rubank, 1939.