1. Fullerenes with metals inside
2. Fowler, P. W.; Manoloupoulos D. E.An Atlas of Fullerenes; Oxford University Press: Oxford, 1995; p 254.
3. Nagase, S.; Kobayashi, K.; Akasaka, T.; Wakahara, T. InFullerenes;Chemistry, Physics and Technology; Kadish, K. M., Ruoff, R., Eds.; John Wiley and Sons: New York, 2000; p 395.