Duke, W. 1888. Notice of a Recumbent Hog-Backed Monument, and Portions of Sculptured Slabs with Symbols, recently discovered at St Vigeans Church, Forfarshire. Proceedings of the Society of Antiquaries of Scotland. 22, (Nov. 1888), 143–146. DOI:https://doi.org/10.9750/PSAS.022.143.146.