@article{freihofer2015damage,
  title={Damage mapping with a degrading elastic modulus using piezospectroscopic coatings},
  author={Freihofer, Gregory and Sch{\"u}lzgen, Axel and Raghavan, Seetha},
  journal={NDT \& E International},
  volume={75},
  pages={65--71},
  year={2015},
  publisher={Elsevier}
}