?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.au=Veldwijk%2C+R.&rft.aulast=Veldwijk&rft.aufirst=R.&rft.degree=Master&rft.date=2009&rft.title=Intervening+in+informal+barrios%3B+Case+study+Medell%C3%ADn