Calder, C.S.T. 1949. Notice of Two Standing Stones (one with Pictish Symbols) on the Lands of Peterhead Farm, near Gleneagles, Perthshire. Proceedings of the Society of Antiquaries of Scotland. 81, (Nov. 1949), 1–7. DOI:https://doi.org/10.9750/PSAS.081.1.7.