1. Abragam A. & Bleaney B. (1986) Electron Paramagnetic Resonance of transition ions, Dover, New York.
2. Abraham M, Judd B. & Wickman H. (1962) Physical Review 130: 611-612.
3. Baker J.M. (1993) “EPR and ENDOR of the lanthanides” in Electron Spin Resonance, volume 13B, Royal Society of Chemistry, Athenaeum Press, Newcastle upon Tyne.
4. Baker J.M. & Bleaney B. (1958) Proceeding of the Royal Society of London A 245: 156-174.
5. Bleaney B., Scovil H. & Trenam R. (1954) Proceeding of the Royal Society A 223: 15-29.