@article{Piggott_Johnson_1956, title={Excavations in Passage-Graves and Ring-Cairns of the Clava Group, 1952-3}, volume={88}, url={http://journals.socantscot.org/index.php/psas/article/view/8468}, DOI={10.9750/PSAS.088.173.207}, journal={Proceedings of the Society of Antiquaries of Scotland}, author={Piggott, Stuart and Johnson, Allard}, year={1956}, month={Nov.}, pages={173-207} }