1. See, e.g., Szwarc, M., Jagur-Grodzinski, J., in: Ions and Ion Pairs in Organic Reactions, (Szwarc, M. ed.), Vol. 2, New York-London-Sydney-Toronto, J. Wiley 1974
2. Ayscough, P. B.: Electron Spin Resonance in Chemistry, London Methuen 1967
3. Carrington, A., McLachlan, A. D.: Introduction to Magnetic Resonance, New York-Evanston-London-Tokyo, Harper & Row, and J. Weatherhill 1967
4. Gerson, F.: Hochauflösende ESR Spektroskopie, Weinheim, Chemie-Verlag 1967; High Resolution ESR Spectroscopy, Weinheim-New York, Chemie Verlag and J. Wiley 1970
5. Scheffler, K., Stegmann, H. B.: Elektronenspinresonanz, Berlin-Heidelberg-New York, Springer 1970