@misc{indiciae92c3e6a3d052,
  title = {Hydrogen masers with cavity frequency switching servos},
  author = {Peters, Harry E. and Owings, H. B. and Koppang, Paul A.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910016463},
  note = {Source identifier: 19910016463}
}