?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.au=Heidtmann%2C+Katharina+F.F.&rft.aufirst=Katharina+F.F.&rft.aulast=Heidtmann&rft.degree=Master&rft.date=2017&rft.title=A%22toothless%22+tiger%3F+Or+why+do+sub-national+levels+as+the+city+of+Osnabr%C3%BCck%2C+Germany%2C+still+not+comply+with+the+EU+Ambient+Air+and+Cleaner+Air+for+Europe+Directive%3F