ANDERSON, R S G. Notes on the Discovery of a Rock-Sculpture at Gallows Outon, Whithorn, Wigtownshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 56, p. 44–45, 1922. DOI: 10.9750/PSAS.056.44.45. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7531. Acesso em: 2 may. 2024.