²Smyth, Daragh. Earthing the Myths: The Myths, Legends and Early History of Ireland. Irish Academic Press, 2021. p. 208 (Kindle Edition)

From his source:
"“cell 10 aduaidh do Dún Delgan; the followers of Cellachán slain at the battle of Dún Delgan were interred in the cell by the N side of Dundalk, BLis 156; gusan cill don taeibh thuaidh do Dun Dealgan, CCC (ed. Bugge) 51. p. 680