Vitae duorum Offarum
Vitae duorum Offarum est liber mythistoricus a Matthaeo Parisiensi medio saeculo tertio decimo scriptus, de vita duorum hominum qui nomen Offa gesserunt, quorum primus, Offa seu Uffo, fuit rex Daniae, vel historicus vel mythicus, qui fortasse saeculo quarto floruit; alter autem, Offa Merciae rex, condidisse traditur Abbatiam Sancti Albani, ubi auctor habitabat.

Hoc opus in libro manu scripto reperitur Bibliothecae Britannicae, siglo BL Cotton Nero D.i recognito, opera varia de abbatia Sancti Albani conprehendenti.

Editio
 "Vitae duorum Offarum sive Offanorum Merciorum regum, coenobii Sancti Albani fundatorum" in Gulielmus Wats, ed., Matthaei Paris Chronica Maior (Londinii, 1684) pp. 961-988

Bibliographia
Grüner, Hans. Matthei Parisiensis Vitae duorum Offarum (saec. XIII med.) in ihrer Manuskript und Textgeschichte. Munich, 1907.
Grüner, Hans. Die Riganus-Schlacht in den Vitae duorum Offarum des Mathaeus Parisiensis (saec. XIII): ein Beitrag zur Bibel- und Legendenkunde des Mittelalters wie zur Geschichte der altenglichen Heldensage. Hamburg, 1914. 
Hahn, C. "The Limits of Text and Image? Matthew Paris's final project, the Vitae duorum Offarum, as a historical romance." In Excavating the Medieval Image. Manuscripts, artists, audiences. Essays In Honor Of Sandra Hindman, ed. David S. Areford et Nina A. Rowe. Aldershot, 2004. 37-58. ISBN 9780754631439
Rickert, Edith. "The Old English Offa Saga."  Modern Philology 2 (1904-5): 29-77, 321-76
Shippey, Tom. "Wicked Queens and Cousin Strategies in Beowulf and Elsewhere." Heroic Age 5 (2001).  
 Swanton, Michael. The Lives of Two Offas, Vitae Offarum Duorum. Crediton: The Medieval Press, 2010. ISBN 978-0-9557636-8-7
Vaughan, R. Matthew Paris. Cambridge Studies in Medieval Life and Thought 6. Cambridge: Cambridge University Press, 1958.
Angliae scripta
Matthaeus Parisiensis
Libri biographici
Libri picti
Scripta saeculo 13