Beckwith, J. (1955). Six mobiles: New piano pieces for students in two sets. BMI Canada.
Cita Chicago (17th ed.)Beckwith, John. Six Mobiles: New Piano Pieces for Students in Two Sets. Toronto: BMI Canada, 1955.
Cita MLA (9th ed.)Beckwith, John. Six Mobiles: New Piano Pieces for Students in Two Sets. BMI Canada, 1955.
Atenció: Aquestes cites poden no estar 100% correctes.