1. and , Resonance Radiation and Excited Atoms, Cambridge University Press, London 1961.
2. and , The Theory of Magnetic Resonance, Interscience, New York 1972 (p. 381).
3. The Principles of Nuclear Magnetism, Oxford University Press, London (p. 106).
4. The Dipolar Broadening of Magnetic Resonance Lines in Crystals