@misc{indiciae936a8c72e8e5,
  title = {Linear Partial Differential Equations with Analytic Coefficients.},
  author = {F John},
  year = {1943},
  doi = {10.1073/pnas.29.3-4.98},
  url = {https://pubmed.ncbi.nlm.nih.gov/16578100/},
  note = {Source identifier: 16578100}
}