Emerton, E. (1990). The correspondence of Pope Gregory VII: Selected letters from the registrum. Columbia Univ..
Lua i Stíl Chicago (17ú heag.)Emerton, Ephraim. The Correspondence of Pope Gregory VII: Selected Letters from the Registrum. New York: Columbia Univ., 1990.
Lua MLA (9ú heag.)Emerton, Ephraim. The Correspondence of Pope Gregory VII: Selected Letters from the Registrum. Columbia Univ., 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.