@misc{1190901,
  author = {W D George and H Lyons and J J Freeman and J M Shaull},
  title = {The microwave frequency standard at the Central Radio Propagation Laboratory:},
  year = {1947},
  month = {1947-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.CRPL.8-1_9-4},
  language = {en},
}