Robertson, J. 1859. Notice of an unpublished letter from General Mackay to the Laird of Grant, dated at London, 4th December 1690, on the comparative strength of Ecclesiastical parties in Scotland at the Revolution. Proceedings of the Society of Antiquaries of Scotland. 2, (Nov. 1859), 336–338. DOI:https://doi.org/10.9750/PSAS.002.336.338.