Byer, G. C. J. (1999). Charlemagne and baptism: A study of responses to the circular letter of 811/812. International Scholars Publications.
Lua i Stíl Chicago (17ú heag.)Byer, Glenn C. J. Charlemagne and Baptism: A Study of Responses to the Circular Letter of 811/812. San Francisco: International Scholars Publications, 1999.
Lua MLA (8ú heag.)Byer, Glenn C. J. Charlemagne and Baptism: A Study of Responses to the Circular Letter of 811/812. International Scholars Publications, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.