Bryce, Thomas, and Alexander Low. “Notes (I) on a Human Skeleton Found in a Cist With a Beaker Urn at Acharole, West Watten, Caithness; And (II) on the Cranial Form Associated With That Type of Ceramic: With an Appendix on Six Skulls Found With Beakers in the North-East Counties”. Proceedings of the Society of Antiquaries of Scotland, vol. 39, Nov. 1905, pp. 418-3, doi:10.9750/PSAS.039.418.438.