@misc{indiciae695e076e579a,
  title = {Probability generating functions and their iterates.},
  author = {W J Bühler},
  year = {1966},
  doi = {10.1073/pnas.56.6.1912},
  url = {https://pubmed.ncbi.nlm.nih.gov/16591438/},
  note = {Source identifier: 16591438}
}