Paul, J. B. (1891) “Notes (1) on a set of Shuffle-board Counters with Portraits of Kings and Heraldic Devices, about 1640; (2) on a Silver Badge of the Conservator of Scottish Privileges in the Netherlands - exhibited by Sir Robert Fraser Turing, Bart”, Proceedings of the Society of Antiquaries of Scotland, 25, pp. 397–402. doi: 10.9750/PSAS.025.397.402.