1. M. Jones and R. A.Moss, Carbenes, Wiley, New York, 1973, vol. I, p. 179
2. M. Jones and R. A.Moss, Carbenes, Wiley, New York, 1975, vol. II, p. 235
3. An Air Stable Carbene and Mixed Carbene “Dimers”
4. R. Hoffmann , Molecular Orbitals of Transition Metal Complexes, Oxford, 2005