@misc{indiciae958616ce7240,
  title = {A sharp-focusing schlieren optical deflectometer},
  author = {Alvi, F. S. and Settles, G. S. and Weinstein, L. M.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19930040749},
  note = {Source identifier: 19930040749}
}