Mary Brockington, The separating sword in the Tristan romances: possible Celtic analogues re-examined, Modern Language Review, 91/2, 1996 : p. 281-300

Considers the relationship of Tristan and Yseut to the Irish fugitives Diarmaid and Grainne, in particular the question whether the sword that Marc discovers separating his wife from her lover is inspired by a stone found in a similar scene in the Irish story, and demonstrates that this is emphatically not the caseDans IMB 30/1, janvier-juin 1996, n° 2775