Techniques for studying high resolution nuclear magnetic resonance spectra have been considerably broadened in recent years. The most far reaching development—pulse Fourier transform (FT) methods—is discussed in detail. Applications of FT techniques to measurement of relaxation times and to enhancement of weak signals, especially from natural abundance <sup>13</sup>C, are reviewed. Double resonance methods, particularly the nuclear Overhauser effect, and the use of lanthanide shift reagents are also covered in this "mini-review."
Edwin D. Becker, "Some Recent Developments in High Resolution Nuclear Magnetic Resonance," Appl. Spectrosc. 26, 421-430 (1972)