@misc{indiciae4ddb28b7a6c9,
  title = {Exact solutions to operator differential equations.},
  author = {CM Bender and GV Dunne},
  year = {1989},
  doi = {10.1103/physrevd.40.2739},
  url = {https://pubmed.ncbi.nlm.nih.gov/10012126/},
  note = {Source identifier: 10012126}
}