@misc{indiciaebf8e52f50f5c,
  title = {Real-Valued Semigroups and (Causal) Diffusion},
  author = {Kowar, Richard},
  year = {2011},
  doi = {10.1063/1.3636876},
  url = {https://www.osti.gov/biblio/21611616},
  note = {Source identifier: 21611616}
}