@misc{indiciae30ed9ed1d660,
  title = {eta - eta ' mixing angle.},
  author = {FJ Gilman and R Kauffman},
  year = {1987},
  doi = {10.1103/physrevd.36.2761},
  url = {https://pubmed.ncbi.nlm.nih.gov/9958494/},
  note = {Source identifier: 9958494}
}