^Roger M. Nielson, George E. McManis, Lance K. Safford, Michael J. Weaver. Solvent and electrolyte effects on the kinetics of ferrocenium-ferrocene self-exchange. A reevaluation. J. Phys. Chem. 1989, 93 (5): 2152. doi:10.1021/j100342a086.
^J. Le Bras, H. Jiao, W. E. Meyer, F. Hampel and J. A. Gladysz, "Synthesis, Crystal Structure, and Reactions of the 17-Valence-Electron Rhenium Methyl Complex [(η5-C5Me5)Re(NO)(P(4-C6H4CH3)3)(CH3)]+ B(3,5-C6H3(CF3)2)4-: Experimental and Computational Bonding Comparisons with 18-Electron Methyl and Methylidene Complexes", J. Organomet. Chem. 2000, vol. 616, p 54-66. doi:10.1016/S0022-328X(00)00531-3