Barlowe, Claude W. ed., Iberian Fathers, v. 2, Braulio of Saragossa, Fructuosus of Braga, Washington D. C. 1969
P. Beltrán, 'Iudila y Sunifredo, reyes visigodos (Estudio numismático).', Empúries: revista de món clàssic i antiguitat tardana 3 (1941), 97-104
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E.A. Thompson, The Goths in Spain, Oxford 1969.