1. R. McWeeny and B. T. Sutcliffe, Methods of Molecular Quantum Mechanics, Academic Press, London, New York (1969).
2. G. M. Zhidomirov, P. V. Shchastnev, and N. D. Chuvylkin, Quantum Chemical Calculations of Magnetic Resonance Parameters [in Russian], Nauka, Novosibirsk (1978).
3. S. P. McGlynn, T. Azumi, and M. Kinoshita, Molecular Spectroscopy of the Triplet State, Prentice-Hall, Englewood Cliffs, N.J. (1969).
4. F. Gerson and W. Huber, Electron Spin Resonance Spectroscopy of Organic Radicals, Wiley-VCH, Weinheim (2003).
5. O. Loboda, B. Minaev, and O. Vahtras, Chem. Phys., 286, No. 1, 127–137 (2003).