1. Electron Paramagnetic Resonance of Transition Ions;Abragam,1970
2. J.W. Orton, Electron Paramagnetic Resonance: An Introduction to Transition Group Ions in Crystals, Gordon and Breach, N. Y., 1968.
3. Electron Spin Relaxation Phenomena in Solids;Standley,1969
4. Relaxation Data Tabulation;Bertini,1994
5. Relaxation, Background, and Theory;Bertini,1994