@misc{indiciaee03b32adbae0,
  title = {Schwinger and anomaly-free Kohn variational principles and a generalized Lanczos algorithm for nonsymmetric operators.},
  author = {H Meyer and J Horáek and LS Cederbaum},
  year = {1991},
  doi = {10.1103/physreva.43.3587},
  url = {https://pubmed.ncbi.nlm.nih.gov/9905446/},
  note = {Source identifier: 9905446}
}