1. Leonard Euler (1707–1783), the father of Topology, showed that for any regular or irregular closed polyhedra, the number of faces (F) plus the number of vertices (V) is always equal to the number of edges (E) plus two. This can be easily seen by drawing any number of closed figures which share sides on the face of a balloon. After counting F, V and E one can verify that F + V = E + 2. This is known as Euler’s Formula and was first proven by Legendre
2. H.W. Kroto, The stability of the fullerenes C-24, C-28, C-32, C-36, C-50, C-60 and C-70. Nature 329, 529–531 (1987)
3. T.G. Schmalz, W.A. Seitz, D.J. Klein, G.E. Hite, Elemental carbon cages. J. Am. Chem. Soc. 110, 1113–1127 (1988)
4. E. Osawa, Superaromaticity. Kagaku (Kyoto) 25, 854–863 (1970)
5. D.A. Bochvar, E.G. Gal'pern, Dokl. Akad. Nauk SSSR 209, 610–612 (1973)