@MastersThesis{kauppinen-an-ontology-versioning-framework-2004,
  author = 	 {Tomi Kauppinen},
  title = 	 {An Ontology Versioning Framework},
  school = 	 {University of Helsinki},
  publisher = {Department of Computer Science, University of Helsinki}
  year = 	 {2004},
  location   =   {Helsinki, Finland},
  OPTmonth =        {June}, 
  OPTurl=        {http://www.seco.hut.fi/publications/2004/kauppinen-an-ontology-versioning-framework-2004.pdf},
  OPTproject =   {http://www.seco.hut.fi/projects/finnonto}
}