@techreport{2007-A.J.J.vanBreemen-TowardConceptualization,
  author		= "Breemen, A.J.J. van and {J.J. Sarbo} and Weide, Th.P. van der",
  title			= "{Toward a theory of natural conceptualization}",
  number		= "ICIS-R07002",
  month			= "January",
  institution		= "Radboud University Nijmegen",
  year			= "2007",
  research_group	= "iris",
  class			= "Report"
}