@article{9786,
  author = {Richard McCray},
  title = {The 35-day Periodicity of Hercules X-1},
  year = {1973},
  journal = {nature physical science},
  volume = {243},
  pages = {94-96},
  month = {06/1973},
  url = {http://www.nature.com/nature-physci/journal/v243/n128/pdf/physci243094b0.pdf},
  doi = {10.1038/physci243094b0},
  note = {<p>JILA Pub. 989</p>},
}