@misc{indiciae218903bc905f,
  title = {Periodic shock with added clock.},
  author = {Hendry, D. P. and Switalski, R. C. and Yarczower, M.},
  year = {1969},
  url = {https://ntrs.nasa.gov/citations/19690094960},
  note = {Source identifier: 19690094960}
}