@article{seguin_podio-guidugli_paroni_2017, 
  title={On the nonlocal curvatures of   surfaces with or without boundary}, 
  volume={17}, 
  DOI={10.3934/cpaa.2018037}, 
  publisher={American Institute of Mathematical Sciences (AIMS)}, 
  author={Seguin and Podio-Guidugli and Paroni}, 
  year={2017}
  }