@misc{indiciae620b5cae7550,
  title = {Algebraic time-ordering techniques and harmonic oscillator with time-dependent frequency.},
  author = {G Dattoli and S Solimeno and A Torre},
  year = {1986},
  doi = {10.1103/physreva.34.2646},
  url = {https://pubmed.ncbi.nlm.nih.gov/9897578/},
  note = {Source identifier: 9897578}
}