(1984). Yamaha Grade Examinations 1981 - 1983. Yamaha.
Cita Chicago (17th ed.)Yamaha Grade Examinations 1981 - 1983. Tokyo: Yamaha, 1984.
Cita MLA (8th ed.)Yamaha Grade Examinations 1981 - 1983. Yamaha, 1984.
Atenció: Aquestes cites poden no estar 100% correctes.