1- ASTM Standard E2001-13, “Standard Guide for Resonant Ultrasonic Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts”, 2013.
2- A. N. Damir, A. Elkhatib and G. Nassef, “Prediction of Fatigue Life Using Modal Analysis for Grey and Ductile Cast Iron,” International Journal of Fatigue, Vol. 29, No. 3, 2007, pp. 499-507.
3- R.W. Bono and G.R. Stultz, “Resonant inspection applied to 100% testing of nodularity of cast ductile iron”, Tech. Rep., SAE, Paper No. 2008-01-2577, Warrendale, PA, 2008.
4- I. Hertlin, D. Schultze, “Acoustic resonance testing: the upcoming volume-oriented NDT method, 3rd Pan-American Conference for Nondestructive Testing”, Brazil, 2003.