@Article{PetkovKruizinga1997bc,
  author =   {N. Petkov and P. Kruizinga},
  title =    {Computational models of visual neurons specialised in the detection 
              of periodic and aperiodic oriented visual stimuli: bar and grating cells},
  journal =  {Biological Cybernetics},
  year =     {1997},
  volume =   {76},
  number =   {2},
  pages =    {83-96}
}