@article{11496,
  author = {P. Wilson and C. Cannon},
  title = {The structure of a sunspot III: Observations of the Wilson Effect},
  year = {1968},
  journal = {Solar Physics},
  volume = {4},
  pages = {3-17},
  month = {Jan-05-1968},
  issn = {0038-0938},
  url = {http://adsabs.harvard.edu/full/1968SoPh....4....3W},
  doi = {10.1007/BF00146994},
}