SOUTHESK, Earl of. Douglas, Percy, and the Cavers Ensign. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 36, p. 246–280, 1902. DOI: 10.9750/PSAS.036.246.280. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6836. Acesso em: 3 may. 2024.