F. R. Coles, “Record of (I) the Excavation of two Stone Circles in Kincardineshire: (1) in Garrol Wood, Durris; (2) in Glassel Wood, Banchory-Ternan; and (II) Report on Stone Circles in Aberdeenshire, with measured Plans and Drawings; obtained under the Gunning Fellows”, PSAS, vol. 39, pp. 190–218, Nov. 1905.