^
McWeeny, R. (1992). Methods of Molecular Quantum Mechanics (2nd ed.). Academic Press. ISBN978-0-470-01187-4
^
Plakhutin, B. N. (2002). Sen, K. D.. ed. Reviews of Modern Quantum Chemistry. 1. Word Scientific. pp. 16–42. ISBN978-981-02-4889-5
^Glaesemann, Kurt R.; Schmidt, Michael W. (2010). “On the Ordering of Orbital Energies in High-Spin ROHF†”. The Journal of Physical Chemistry A114 (33): 8772–8777. doi:10.1021/jp101758y. PMID20443582.
^
Jensen, F. (2007). Introduction to Computational Chemistry (2nd ed.). Wiley. ISBN978-0-471-98425-2
^Crawford, T. Daniel; Schaefer, Henry F.; Lee, Timothy J. (1996). “On the energy invariance of open-shell perturbation theory with respect to unitary transformations of molecular orbitals”. The Journal of Chemical Physics105 (3): 1060. Bibcode: 1996JChPh.105.1060C. doi:10.1063/1.471951.