SLADE, H Gordon. The Tower and House of Drum, Aberdeenshire. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 115, p. 297–356, 1987. DOI: 10.9750/PSAS.115.297.356. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/9185. Acesso em: 19 apr. 2024.