@misc{92721,
  author = {Shirley Radack},
  title = {Improving the Security of Electronic Mail: Updated Guidelines Issued by NIST},
  year = {2007},
  month = {2007-03-28},
  publisher = {ITL Bulletin, National Institute of Standards and Technology, Gaithersburg, MD},
  url = {https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=51143},
  language = {en},
}