@misc{indiciae856aa6e91311,
  title = {Second-harmonic generation at simple metal surfaces.},
  author = {A Liebsch},
  year = {1988},
  doi = {10.1103/physrevlett.61.1233},
  url = {https://pubmed.ncbi.nlm.nih.gov/10038736/},
  note = {Source identifier: 10038736}
}