MACRITCHIE, David. The Celtic Numerals of Strathclyde. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 49, p. 276–285, 1915. DOI: 10.9750/PSAS.049.276.285. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7362. Acesso em: 16 apr. 2024.