@misc{indiciae18864f6706b0,
  title = {Feynman path integral and the interaction picture.},
  author = {RE Pugh},
  year = {1986},
  doi = {10.1103/physrevd.33.1027},
  url = {https://pubmed.ncbi.nlm.nih.gov/9956722/},
  note = {Source identifier: 9956722}
}