?url_ver=Z39.88-2004&rft_id=10.1016%2Fj.renene.2014.12.040&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Ullah%2C+Z.&rft.aulast=Ullah&rft.aufirst=Z.&rft.title=Renewable+Energy&rft.date=2015&rft.volume=77&rft.issn=09601481&rft.pages=521-526&rft.atitle=Biodiesel+production+from+waste+cooking+oil+by+acidic+ionic+liquid+as+a+catalyst&rft.genre=article