MAXWELL, Herbert E. Shaft of a Celtic Cross from Longcastle, Wigtownshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 55, p. 276–277, 1921. DOI: 10.9750/PSAS.055.276.277. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7513. Acesso em: 2 may. 2024.