Epistolae Austrasicae (‘The Austrasian Letters’).
Latin Text: ed. W. Gundlach, MGH Epp. 3 (Berlin, 1892) [link]
Vatican, BAV, Pal. lat. 869 [link] – this is the sole surviving manuscript of the Epistolae Austrasicae. It was produced in Lorsch early in the ninth century.
Letters of Boniface and Lull
Latin text: ed. by M. Tangl, MGH Epp. Sel. 1 (Berlin, 1916) [link]