The Hill Fort on the Barmekin of Echt, Aberdeenshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 54, p. 45–50, 1920. DOI: 10.9750/PSAS.054.45.50. Disponível em: https://soas-test.journals.ed.ac.uk/index.php/psas/article/view/7478. Acesso em: 27 oct. 2025.