@misc{indiciae97010e159f9a,
  title = {Trapped-ion frequency standards},
  author = {Wineland, David J. and Itano, W. M. and Bergquist, J. C. and Bollinger, J. J. and Heinzen, D. J. and Manney, C. H. and Moore, F. L. and Raizen, M. G. and Weimer, C. S.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910016446},
  note = {Source identifier: 19910016446}
}