ARMSTRONG, Robert Bruce. Notes on the Old Church and Cemetery of Airth, Stirlingshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 13, p. 165–170, 1879. DOI: 10.9750/PSAS.013.165.170. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/5877. Acesso em: 7 may. 2024.