@misc{1154066,
  author = {Henry Goldberg},
  title = {On the nature of the crystal field approximation:},
  year = {1960},
  month = {1960-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.TN.67},
  language = {en},
}