@misc{1173236,
  author = {Gifford Hefley},
  title = {The Development of Loran-C navigation and timing:},
  year = {1972},
  month = {1972-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.MONO.129},
  language = {en},
}