@article{10552,
  author = {B. Shore and J. Eberly},
  title = {Analytic approximations in multi-level excitation theory},
  year = {1978},
  journal = {Optics Communications},
  volume = {24},
  pages = {83-88},
  month = {Jan-01-1978},
  issn = {00304018},
  url = {http://linkinghub.elsevier.com/retrieve/pii/0030401878902729},
  doi = {10.1016/0030-4018(78)90272-9},
}