Approximate Orientation Steerability Based on Angular Gaussians
@TechReport{yuTR2004,
  author = {W. Yu and K. Daniilidis and G. Sommer},
  title = {Approximate Orientation Steerability Based on Angular Gaussians},
  institution = {Christian-Albrechts-Universit{"a}t zu Kiel, 
       Institut f{"u}r Informatik und Praktische Mathematik},
  type = {Technical Report},
  number = {Number 2004},
  month =      {November},
  year = 1999,
  }