@misc{indiciaeaa99e1b22d0a,
  title = {Laser modes with helical wave fronts.},
  author = {M Harris and CA Hill and PR Tapster and JM Vaughan},
  year = {1994},
  doi = {10.1103/physreva.49.3119},
  url = {https://pubmed.ncbi.nlm.nih.gov/9910603/},
  note = {Source identifier: 9910603}
}