@misc{indiciae9f42f5249191,
  title = {An optical heterodyne densitometer},
  author = {Migdall, A. L. and Zheng, Ying Cong and Hardis, J. and Snyder, J. J.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19890003952},
  note = {Source identifier: 19890003952}
}