Cunliffe, Barry : The Ancient Celts , 1999. Penguin paperback. (London 1997).
Dillon, Myles & Nora K. Chadwick: The Celtic Realms, 1967; 2000. London : Weidenfeld and Nicolson; Phoenix Press paperback . kap. 2-4 og 6-9; kart 1-6.
Ó Cróinín, Dáibhí: Early medieval Ireland, 1995. London: Longman. ISBN: 0-582-01565-0. kap. 1-3 og 8-9.
Kinsella, Thomas: The Táin: From the Irish Epic "Táin Bo Cuailinge" , 2002. Oxford Paperbacks . ISBN: 0192803735.
Kompendium 1
Rankin, D. : Celts and the classical world, 1987 (Paperback 1996). Routledge, London & N.Y.. kap. 4-6.
Green, M.: Celtic Art - Reading the messages , 1996. The Everyman Art Library, Weidenfeld Nicholson Illustrated. ISBN: 0297833650. Kap. 4-5 (s.114-167).
Piggot, Stuart: The Druids, 1975 Praeger; 1985 Thames and Hudson. kap. 1-3.
Kompendium 2
Green, M. & R. Howell: Celtic Wales. A pocket guide , 2000. Cardiff: University of Wales Press . ISBN: 0708315321. kap. 5-6.
Raftery, B.: Pagan Celtic Ireland: the enigma of the Irish Iron Age, 1994. London: Thames and Hudson . ISBN: 0-500-05072-4, 0-500-27983-7 . kap. 4-8.
Thomas, C.: Britain and Ireland in early Christian times: AD 400-800, 1971. Library of medieval civilization, London: Thames and Hudson. kap. 2.
Kompendium 3
Ó Corráin, Donnchad (1989): Prehistoric and early Christian Ireland, in: Foster, R.F. (ed.): The Oxford illustrated history of Ireland, Oxford: Oxford University Press, p.1-52
Kompendium: Fastlandskeltisk og øykeltisk
Charles-Edwards, Thomas: Language and society among the Insular Celts, AD 400-1000,(ch. 36) in: Green, Miranda J. (ed.):The Celtic World, ISBN 0-415-146267-5, London : Routledge, 1995 chap. 36, pp. 703-736
Quiggin, E.C.: Celt, in: Encyclopaedia Britannica, 1910, s.611-652
Schmidt, Karl Horst: Insular Celtic. P and Q Celtiq, in Ball, Martin J. & James Fife (eds.): The Celtic languages, Series: Routledge language family descriptions, London : Routledge, 1993. ISBN 0-415-01035-7. (pp. 64-87)