?url_ver=Z39.88-2004&rft_id=0575&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Humpherys%2C+A.S.&rft.aufirst=A.S.&rft.aulast=Humpherys&rft.atitle=Evaluation+of+Drop-Check+Structures+for+Farm+Irrigation+Systems&rft.date=1986&rft.volume=29&rft.pages=505-511%2C516&rft.title=Transaction+of+the+ASAE&rft.issue=2&rft.genre=article