Coles, F.R. 1903. Report on the Stone Circles of North-Eastern Scotland, chiefly in Auchterless and Forgue, with measured Plans and Drawings, obtained under the Gunning Fellowship. Proceedings of the Society of Antiquaries of Scotland. 37, (Nov. 1903), 82–142. DOI:https://doi.org/10.9750/PSAS.037.82.142.