Smith, J. (1867) “Notice of a Small Bronze Blade found in a Cinerary Urn at Balblair, Sutherlandshire; also Two Small Bronze Plates, in the Collection of His Grace the Duke of Sutherland”, Proceedings of the Society of Antiquaries of Scotland, 7, pp. 475–477. doi: 10.9750/PSAS.007.475.477.