@techreport{1991-Boiten-IntersectionsProblems,
  author		= "{Boiten}, E.A.",
  title			= "{Intersections of Sets and Bags of Extended Substructures -- a Class of Problems and Can Bag Comprehension be used at all?}",
  number		= "CSI--R9121",
  month			= "September",
  institution		= "Radboud University Nijmegen",
  organization		= "Radboud University Nijmegen",
  year			= "1991",
  code			= "icis.91-21",
  research_group	= "icis",
  class			= "Report"
}