Hugh Lyon Playfair, n.d., Group picture taken at St. Andrews of men and boys, all wearing Glengarry caps, [Album of the Edinburgh Calotype Club, vol. 2], Calotype, National Library of Scotland, LL/49529
Hugh Lyon Playfair, n.d., Sir David Brewster. He was a close friend of William Henry Fox Talbot, the inventor of the calotype, [Album of the Edinburgh Calotype Club, vol. 1], Calotype, National Library of Scotland, LL/49505
