Macadam, W. (1880) “Notice, with Analyses, of a Series of Church Tokens of various Parishes; of the Collection Plates belonging to the church of Duddingston and the Trinity College Church of Edinburgh; and of the Trinity College Church Hospital Bell”, Proceedings of the Society of Antiquaries of Scotland, 14, pp. 163-169. doi: 10.9750/PSAS.014.163.169.