Calder, C. S. T., & 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, 217–236. https://doi.org/10.9750/PSAS.070.217.236