1. See references [2–4] for textbooks.
2. A. Abragam, The Principles of Nuclear Magnetism, Clarendon Press, Oxford, 1961.
3. C. P. Slichter, Principles of Magnetic Resonance, Harper & Row Publishers, New York, 1963 (expanded edition, Springer-Verlag, 1978).
4. A. Narath, Nuclear Magnetic Resonance in Magnetic and Metallic Solids in Hyperfine Interactions, ed. by A. J. Freeman and R.B. Frankel, Academic Press, 1967.
5. T. Moriya, J. Phys. Soc. Japan 18(1963) 516.