PIGGOTT, Stuart; JOHNSON, Allard H. Excavations in Passage-Graves and Ring-Cairns of the Clava Group, 1952-3: With Appendices. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 88, p. 173–207, 1956. DOI: 10.9750/PSAS.088.173.207. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/8468. Acesso em: 24 apr. 2024.