@article{9891,
  author = {I. Percival},
  title = {Regular and irregular spectra},
  year = {1973},
  journal = {Journal of Physics B: Atomic and Molecular Physics},
  volume = {6},
  pages = {L229 - L232},
  month = {Jan-09-1973},
  issn = {0022-3700},
  url = {http://stacks.iop.org/0022-3700/6/i=9/a=002?key=crossref.4f95a72f819b3a947bb2256b30054354},
  doi = {10.1088/0022-3700/6/9/002},
}