V. I. Sokolov, N. V. Abramova, E. V. Mutseneck, A. S. Romanov, A. R. Kudinov, P. Zanello, J. Barbetti, S. M. Peregudova, “Synthesis and electrochemistry of 2-polymethylmetallocenyl-substituted pyrrolidino[60]fullerenes”, Mendeleev Commun., 17:4 (2007), 202–203