1. A. Abragam, B. Bleany, Electron Paramagnetic Resonance of Transition Ions (Clarendon, Oxford, 1970)
2. A. Abragam, Principles of Nuclear Magnetism (Clarendon, Oxford, 1961)
3. An extensive list of books on Mössbauer spectroscopy can be found in
http://www.mossbauer.org/books.html
4. S.S. Hanna, J. Heberle, C. Littlejohn, G.J. Perlow, R.S. Preston, D.H. Vincent, Phys. Rev. Lett. 4, 177 (1960)
5. S.S. Hanna, J. Heberle, G.J. Perlow, R.S. Preston, D.H. Vincent, Phys. Rev. Lett. 4, 513 (1960)