?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Bin+Iman%2C+H.&rft.aulast=Bin+Iman&rft.aufirst=H.&rft.atitle=Various+mathematical+model+of+torsional+vibration+in+oil+well+drill+string+and+their+validation+techniques&rft.pages=13389-13391&rft.issue=22&rft.volume=11&rft.issn=18196608&rft.date=2016&rft.title=ARPN+Journal+of+Engineering+and+Applied+Sciences&rft.genre=article