?url_ver=Z39.88-2004&rft_id=10.1016%2Fj.jngse.2018.01.043&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Ullah+Khan%2C+I.&rft.aulast=Ullah+Khan&rft.aufirst=I.&rft.volume=52&rft.issn=18755100&rft.atitle=Status+and+improvement+of+dual-layer+hollow+fiber+membranes+via+co-extrusion+process+for+gas+separation%3A+A+review&rft.pages=215-234&rft.title=Journal+of+Natural+Gas+Science+and+Engineering&rft.date=2018&rft.genre=article