• DOI http://dx.doi.org/10.18177/sym.2011.51.fr.8945
  • PDF https://www.jstor.org/stable/26513073

  • DOI http://dx.doi.org/10.18177/sym.2011.51.fr.8944
  • PDF https://www.jstor.org/stable/26513074

  • PDF https://www.jstor.org/stable/41225233