@misc{indiciaec9f18a39a7a1,
  title = {On a variational formula for the principal eigenvalue for operators with maximum principle.},
  author = {M D Donsker and S R Varadhan},
  year = {1975},
  doi = {10.1073/pnas.72.3.780},
  url = {https://pubmed.ncbi.nlm.nih.gov/16592231/},
  note = {Source identifier: 16592231}
}