1. Hedberg, K., Hedberg,L., Bethune, D.S., Brown, C.A., de Vries, M., Dorn, H.C., and Johnson, R.D., (1991), Experimental values of the bond lengths in free molecules of Buckminsterfullerene, C60, from gas-phase diffraction, Science 254, 410–412.
2. Braga, M., Larsson, S., Rosén, A., and Volosov, A., (1991), Electronic transitions in C60. on the origin of the strong interstellar absorption at 217 nm, Astron.Astrophys. 245, 232–238
3. Leach, S., Vervloet, M., Després, A., Bréheret, E., Hare, J.P., Dennis, T.J., Kroto, H.W., Taylor, R. and Walton, D.R.M., (1992) Electronic spectra and transitions of the fullerene C60, Chem.Phys., 160, 451–466.
4. Gasyna, Z., Schatz, P.N., Hare, J.P., Dennis, T.J., Kroto, H.W., Taylor, R., and Walton, D.R.M., (1991), The magnetiv circular dichroism and absorption spectra of C60 isolated in Ar matrices, Chem.Phys.Lett., 183, 283–291.
5. Herzberg, G. (1966) Electronic Spectra and Electronic Structure of Polyatomic Molecules, Van Nostrand, Princeton, NJ.