1. Rogers, C. A. Proc. Lond. Math. Soc. 8, 609–620 (1958).
2. Barlow, W. Nature 29, 186–188 (1883).
3. Buckminster Fuller, R. Synergetics (Macmillan, London, 1975).
4. Hsiang, W.-Y. Int. J. Math. 93, 739–831 (1993).
5. Fejes Tóth, G. Math. Rev. 95, no. 52032 (1995).