@misc{indiciae4944538bfda5,
  title = {UNITARY TRANSFORMATIONS AND THE ACTION PRINCIPLE.},
  author = {J Schwinger},
  year = {1960},
  doi = {10.1073/pnas.46.6.883},
  url = {https://pubmed.ncbi.nlm.nih.gov/16590686/},
  note = {Source identifier: 16590686}
}