@article{Woehl:398,
      author        = "Woehl, H. and Brajsa, R. and Hanslmeier, A. and Gissot,
                       S.",
      title         = "{A precise measurement of the solar differential rotation
                       by tracing small bright coronal structures in SOHO-EIT
                       images. Results and comparisons for the period 1998-2006}",
      year          = "2010",
}