Mackay, Æ J.G. 1893. Notice of a Portrait Group of Margaret Tudor, the Regent Albany, and a Third Figure; the Property of the Marquis of Bute, at Cardiff Castle, Glamorganshire. Proceedings of the Society of Antiquaries of Scotland. 27, (Nov. 1893), 186–205. DOI:https://doi.org/10.9750/PSAS.027.186.205.