@misc{indiciae1dab78b3fa8f,
  title = {Variational approach for approximating energy levels.},
  author = {C Stubbins and K Das},
  year = {1993},
  doi = {10.1103/physreva.47.4506},
  url = {https://pubmed.ncbi.nlm.nih.gov/9909461/},
  note = {Source identifier: 9909461}
}