1. Farrar TC, Becker ED (1971) Pulse and Fourier transform NMR: introduction to theory and methods. Academic, New York, p 46
2. Levy GC (1974) Topics in carbon-13 NMR spectroscopy, vol. 1. Wiley, New York, chap 3
3. Yoder CH, Schaeffer CP Jr (1987) Introduction to multinuclear NMR. Benjamin/ Cummings, Malno Park, CA, p 67
4. Derome AE (1987) Modern NMR techniques for chemistry research. Pergamon, New York, chaps 4, 5
5. Slichter CP (1980) Principles of magnetic resonance. Springer, Berlin Heidelberg, New York