@misc{indiciaeca79bc2c6627,
  title = {Resonance regions determined by a projection-operator formulation.},
  author = {E Engdahl and E Brändas},
  year = {1988},
  doi = {10.1103/physreva.37.4145},
  url = {https://pubmed.ncbi.nlm.nih.gov/9899538/},
  note = {Source identifier: 9899538}
}