Wright: St. Patrick's Purgatory (London, 1844); Krapp: The Legend of
St. Patrick's Purgatory (Baltimore, 1900); Becker: Mediaeval Visions
of Heaven and Hell (Baltimore, 1899); Shackford: Legends and Satires
(Boston, 1913); Meyer and Nutt: The Voyage of Bran, edited and
translated by K. Meyer, with an Essay on the Irish Version of the
Happy Other World and the Celtic Doctrine of Rebirth, by A. Nutt, 2
vols. (London, 1895); Boswell: An Irish Precursor of Dante (London,
1908).