Geddes, J. et al. 2016. Tullich, Aberdeenshire: a reappraisal of an early ecclesiastical site and its carvedstones in the light of recent excavations. Proceedings of the Society of Antiquaries of Scotland. 145, (Nov. 2016), 229–281. DOI:https://doi.org/10.9750/PSAS.145.229.281.