Observations on the Pre-Neolithic Industries of Scotland. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 56, p. 261–281, 1922. DOI: 10.9750/PSAS.056.261.281. Disponível em: https://soas-test.journals.ed.ac.uk/index.php/psas/article/view/7526. Acesso em: 27 oct. 2025.