?url_ver=Z39.88-2004&rft_id=10.1088%2F1757-899X%2F100%2F1%2F012041&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Firmansyah&rft.au=Firmansyah%2C+F.&rft.aufirst=F.&rft.issn=17578981&rft.title=Performance+of+CO2+enrich+CNG+in+direct+injection+engine&rft.date=2015&rft.genre=proceeding