@misc{indiciae4e4fbd727420,
  title = {Nonlinear instabilities relating to negative-energy modes.},
  author = {D Pfirsch},
  year = {1993},
  doi = {10.1103/physreve.48.1428},
  url = {https://pubmed.ncbi.nlm.nih.gov/9960731/},
  note = {Source identifier: 9960731}
}