@misc{indiciae219664bdf0fb,
  title = {Diffraction-free beams remain diffraction free under all paraxial optical transformations.},
  author = {KB Wolf},
  year = {1988},
  doi = {10.1103/physrevlett.60.757},
  url = {https://pubmed.ncbi.nlm.nih.gov/10038644/},
  note = {Source identifier: 10038644}
}