Anderson, Joseph. “Notes on the Evidence of Spinning and Weaving in the Brochs or Pictish Towers Supplied by the Stone Whorls and the Long-Handled ’Broch Combs’ Found in Them”. Proceedings of the Society of Antiquaries of Scotland, vol. 9, Nov. 1871, pp. 548-61, doi:10.9750/PSAS.009.548.561.