Calder, C.S.T. and MacDonald, G. 1936. The Dwarfie Stane, Hoy, Orkney: Its period and purpose: With a note on ’Jo Ben’ and the Dwarfie Stane. Proceedings of the Society of Antiquaries of Scotland. 70, (Nov. 1936), 217–236. DOI:https://doi.org/10.9750/PSAS.070.217.236.