@misc{indiciaef41c415a2284,
  title = {Phase conjugate Twyman-Green interferometer for testing conicoidal surfaces},
  author = {Shukla, R. P. and Dokhanian, Mostafa and Venkateswarlu, Putcha and George, M. C.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910070890},
  note = {Source identifier: 19910070890}
}