BLACK, George F. Notes on a Silver-mounted Charm-Stone of Rock-Crystal from Inverleny, with Notices of other Scottish Balls of Rock-Crystal and of Superstitions connected therewith. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 29, p. 439–448, 1895. DOI: 10.9750/PSAS.029.439.448. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6601. Acesso em: 7 may. 2024.