@misc{indiciaeb7e09f24ccf8,
  title = {Letter: The NSD Formula.},
  author = {F Ellis and R J Berry and T J Patterson and G Wiernik and J W Hopewell},
  year = {1974},
  doi = {10.1259/0007-1285-47-557-293-b},
  url = {https://pubmed.ncbi.nlm.nih.gov/4857339/},
  note = {Source identifier: 4857339}
}