@misc{indiciae8057492fb90b,
  title = {Congruences between modular forms: raising the level and dropping Euler factors.},
  author = {F Diamond},
  year = {1997},
  doi = {10.1073/pnas.94.21.11143},
  url = {https://pubmed.ncbi.nlm.nih.gov/11607760/},
  note = {Source identifier: 11607760}
}