Tham khảo Ballad

  1. ↑ W. Apel, Harvard Dictionary of Music (Harvard, 1944; 2nd edn., 1972), p. 70.
  2. ↑ A. Jacobs, A Short History of Western Music (1972, Penguin, 1976), p. 21.
  3. ↑ W. Apel, Harvard Dictionary of Music (1944, Harvard, 1972), pp. 70-72.
  4. ↑ J. E. Housman, British Popular Ballads (1952, London: Ayer Publishing, 1969), p. 15.
  5. ↑ A. Jacobs, A Short History of Western Music (Penguin 1972, 1976), p. 20.
  6. ↑ A. N. Bold, The Ballad (Routledge, 1979), p. 5.