@misc{indiciae0de0548a809a,
  title = {Double-null coordinates for the Vaidya metric.},
  author = {B Waugh and K Lake},
  year = {1986},
  doi = {10.1103/physrevd.34.2978},
  url = {https://pubmed.ncbi.nlm.nih.gov/9957018/},
  note = {Source identifier: 9957018}
}