7Heraughty, Patrick. Inishmurray: Ancient Monastic Island. Dublin: O'Brien, 1982. 38.
According to Cormac Bourke, "Walker's ownership of the crozier and bell from Inishmurray is confirmed by an unpublished letter of 28 October 1843 from Petrie to Lord Adare (later the third Earl of Dunraven)." (Burke, Cormac. "A Crozier and Bell from Inishmurray and Their Place in Ninth-Century Irish Archaeology." Proceedings of the Royal Irish Academy. Section C: Archaeology, Celtic Studies, History, Linguistics, Literature 85C (1985): 146.)