Martyn, J. R. C. (2013). Gregory and Leander: An analysis of the special friendship between Pope Gregory the Great and Leander, Archbishop of Seville. Cambridge Scholars Publishing.
Lua i Stíl Chicago (17ú heag.)Martyn, John R. C. Gregory and Leander: An Analysis of the Special Friendship Between Pope Gregory the Great and Leander, Archbishop of Seville. Newcastle upon Tyne: Cambridge Scholars Publishing, 2013.
Lua MLA (9ú heag.)Martyn, John R. C. Gregory and Leander: An Analysis of the Special Friendship Between Pope Gregory the Great and Leander, Archbishop of Seville. Cambridge Scholars Publishing, 2013.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.