@techreport{3172,
  title = {Confidence Sets for Ratios: A Purely Geometric Approach To Fieller's Theorem},
  abstract = {We present a simple, geometric method to
  construct Fieller's exact confidence sets for
  ratios of jointly normally distributed random
  variables. Contrary to previous geometric
  approaches in the literature, our method is
  valid in the general case where both sample mean
  and covariance are unknown. Moreover, not only
  the construction but also its proof are purely
  geometric and elementary, thus giving intuition
  into the nature of the confidence sets.},
  number = {133},
  organization = {Max-Planck-Gesellschaft},
  institution = {Max Planck Institute for Biological Cybernetics},
  school = {Biologische Kybernetik},
  year = {2004},
  author = {von Luxburg, U. and Franz, VH.}
}