1. Carr, H.Y., Purceil, E.M.: Phys. Rev.94, 630 (1954)
2. Abragam, A.: The Principles of Nuclear Magnetism, Oxford: Clarendon Press 1961.
3. Freeman, R., Hill, H.D.W., in: Dynamic Nuclear Magnetic Resonance Spectroscopy, (Jackman, L.M., Cotton, F.A. eds.) New York. Academic Press 1975.
4. Vold, R.L., Vold, R.R.: Progr. NMR Spectr.12, 79 (1978)
5. Emsley, L., Bodenhausen, G.: Chem. Phys. Lett.165 169 (1990)