@misc{indiciae705a5d83f955,
  title = {Sildenafil can trigger cluster headaches.},
  author = {Randolph W Evans},
  year = {2006},
  doi = {10.1111/j.1526-4610.2006.00316\_4.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/16412168/},
  note = {Source identifier: 16412168}
}