@misc{indiciae7c96a2e84408,
  title = {Variational estimates for excited states.},
  author = {G Karl and VA Novikov},
  year = {1995},
  doi = {10.1103/physrevd.51.5069},
  url = {https://pubmed.ncbi.nlm.nih.gov/10018982/},
  note = {Source identifier: 10018982}
}