Sullivan, J. W. N. (1952). Beethoven: His Spiritual Development (2. Aufl.). Mentor Books.
Lua i Stíl Chicago (17ú heag.)Sullivan, J. W. N. Beethoven: His Spiritual Development. 2. Aufl. New York: Mentor Books, 1952.
Lua MLA (8ú heag.)Sullivan, J. W. N. Beethoven: His Spiritual Development. 2. Aufl. Mentor Books, 1952.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.