@misc{indiciaeec5cd5972b2b,
  title = {Improved State Selection For Hydrogen Masers},
  author = {Vessot, Robert F. C. and Mattison, Edward M.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19880000476},
  note = {Source identifier: 19880000476}
}