LAING, Lloyd. How late were Pictish symbols employed?. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 130, p. 637–650, 2002. DOI: 10.9750/PSAS.130.637.650. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/9534. Acesso em: 1 may. 2024.