↑Luuk De Ligt in: The Impact of the Roman Army (200 BC-AD 476): Economic, Social, Political, Religious, and Cultural Aspects, Proceedings of the Sixth Workshop of the International Network Impact of Empire (Roman Empire, 200 B.C.-A.D. 476), Capri, March 29-April 2, 2005
Deel 6 van Impact of Empire (Roman Empire, 27 B.C.-A.D. 406) (Series), BRILL, 2007, ISBN 9004160442, ISBN 9789004160446