^Adkins,Lesley Adkins,Roy A.(1998).Handbook to Life in Ancient Rome.Oxford University Press,USA.ISBN 9780195123326.
^Booking, N. D. pt. ii. pp. 1026, seq.; Marquardt's Becker, Röm. Alterthum, vol. iii. pt. 2, p. 354; Georg Friedrich Grotefend, in Pauly's Realencyklopädie, s. v. Legio.