Spencer, P. (1983). The practice of harmony. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Spencer, Peter. The Practice of Harmony. Englewood Cliffs, NJ: Prentice-Hall, 1983.
Lua MLA (9ú heag.)Spencer, Peter. The Practice of Harmony. Prentice-Hall, 1983.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.