Proceedings of Royal Irish Academy (Dublin); Proceedings of Society
of Antiquaries (Dublin); Ulster Journal of Archaeology, Old Series
and New Series, edited by F.J. Bigger, Belfast; Wakeman: Handbook of
Irish Antiquities (Dublin, 1891); Stokes: Early Christian Art in
Ireland (Dublin, 1887); Petrie: Round Towers and Ancient Architecture
of Ireland (Dublin, 1845).