Emeritus Professor Derek Douglas Alexander Simpson. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 134, p. 3–6, 2005. DOI: 10.9750/PSAS.134.3.6. Disponível em: https://soas-test.journals.ed.ac.uk/index.php/psas/article/view/9622. Acesso em: 1 oct. 2025.