Carmichael, A. A. (1871) “Notices of Teampull Michael, Keallun, North Uist, and of Sculptured Stones in Bearnarey, Harris, and in Benbecula; an ‘Abrach’ Quern, and Quarry for Querns, Heisgeir, North Uist. &c”, Proceedings of the Society of Antiquaries of Scotland, 8, pp. 276–286. doi: 10.9750/PSAS.008.276.286.