@misc{1156031,
  author = {B M Levin},
  title = {Distribution of incoming lettermail at the Baltimore, Maryland city post office:},
  year = {1959},
  month = {1959-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.TN.33},
  language = {en},
}