@misc{indiciae731366712ced,
  title = {Chemical messengers in development: a hypothesis.},
  author = {D McMahon},
  year = {1974},
  doi = {10.1126/science.185.4156.1012},
  url = {https://pubmed.ncbi.nlm.nih.gov/4152810/},
  note = {Source identifier: 4152810}
}