?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aufirst=N.&rft.au=Keulen%2C+N.&rft.aulast=Keulen&rft.degree=Master&rft.title=Clean+tech%3A+a+new+asset+class&rft.date=2009