Mackay, A. (1906) “Notes on a Slab with Incised Crescentic Design, Stone Mould for casting Spear-heads, a Cup-marked Stone, Holy-water Stoup, and other Antiquities in Strathnaver, Sutherlandshire”, Proceedings of the Society of Antiquaries of Scotland, 40, pp. 128–133. doi: 10.9750/PSAS.040.128.133.