1. Low frequency acoustic NDT methods;Lange;Sov. J. NDT,1978
2. The impedance method of non-destructive inspection;Cawley;NDT International,1984
3. The location of defects in structures from measurements of natural frequencies;Cawley;J. Strain Analysis,1979
4. Defect location in structures by a vibration technique;Cawley,1979
5. Measurement and application of mechanical impedance data, Part 2, measurement techniques;Ewins;J. Soc. Env. Eng.,1976