@article{NanthakumarLahmerRabczuk2013,
  author    = {S.S. Nanthakumar and Tom Lahmer and Timon Rabczuk},
  title     = {Detection of flaws in piezoelectric structures using extended FEM},
  journal   = {International Journal for Numerical Methods in Engineering},
  pages     = {373 -- 389},
  year      = {2013},
}