@article{772421,
  author = {David Penn and S Girvin and G Mahan},
  title = {Dispersion Relation Approach to the X-Ray Edge Problem},
  year = {1981},
  number = {24},
  month = {1981-12-15 00:12:00},
  publisher = {Physical Review B (Condensed Matter and Materials Physics)},
  language = {en},
}