A. J. H. Edwards, “Excavation of a Chambered Cairn at Ham, Caithness, and of a Hut-Circle and Two Earth-Houses at Freswick Links, Caithness: With a Note on a Winged Horse carved on one of the Lintels in the Earth-House at Crichton Mains, Midlothian”, PSAS, vol. 59, pp. 85–95, Nov. 1925.