@book{justhis5310,
          editor = {Cha{\"i}m Perelman and Raymond Vander Elst},
           title = {Les notions {\`a} contenu variable en droit.},
         address = {Bruxelles},
       publisher = {Emile Bruylant},
            year = {1984},
          series = {Travaux de Centre national de recherches de logique},
        keywords = {History of Law Geschiedenis van het recht},
             url = {http://www.just-his.be/eprints/5310/}
}