Edwards, A. J. H. 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 1925, 59, 85-95.