A. Carmichael, “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”, PSAS, vol. 8, pp. 276-286, Nov. 1871.