Barclay, Gordon J, M Brooks, and James S Rideout. “The Cup and Ring Marked Stone at Newbigging Farm, Perth & Kinross District, Tayside Region”. Proceedings of the Society of Antiquaries of Scotland 112 (November 30, 1983): 559–561. Accessed April 24, 2024. https://journals.socantscot.org/index.php/psas/article/view/9103.