Johner, D., & Butterfield, H. S. (1906). A new school of Gregorian chant. Fr. Pustet.
Lua i Stíl Chicago (17ú heag.)Johner, Dominicus, agus Henry S. Butterfield. A New School of Gregorian Chant. Ratisbon: Fr. Pustet, 1906.
Lua MLA (8ú heag.)Johner, Dominicus, agus Henry S. Butterfield. A New School of Gregorian Chant. Fr. Pustet, 1906.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.