LACAILLE, A D. Some Antiquities in Strathfillan, Perthshire. Cupped Boulder near Helensburgh, and Cross-slabs in Glen Fruin, Dumbartonshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 58, p. 124–130, 1924. DOI: 10.9750/PSAS.058.124.130. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7612. Acesso em: 24 apr. 2024.