Lloyd, David Robert (2012). "How old are the Platonic solids?". British Society for the History of Mathematics Bulletin. 27 (3): 131–140. doi:10.1080/17498430.2012.670845. S2CID119544202.
Secrets of Stonehenge (science documentary / transcript). Nova. PBS. November 2010. — shows an experimental use of them as roller-bearings for megalith transport. Search transcript for key phrase "carved stone balls".
Lloyd, David Robert (2012). "How old are the Platonic solids?". British Society for the History of Mathematics Bulletin. 27 (3): 131–140. doi:10.1080/17498430.2012.670845. S2CID119544202.