@misc{indiciae5ac6f0fba8ed,
  title = {When is a derivative not a derivative?},
  author = {G F Phillips},
  year = {1973},
  doi = {10.1177/002580247301300310},
  url = {https://pubmed.ncbi.nlm.nih.gov/4729113/},
  note = {Source identifier: 4729113}
}