?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=W+D&rft.au=Dar%2C+W+D&rft.aulast=Dar&rft.atitle=Declining+Agricultural+Productivity+and+Global+Food+Security&rft.title=Journal+of+Crop+Improvement&rft.issn=1542-7536&rft.date=2013&rft.volume=27&rft.pages=242-254&rft.issue=2&rft.genre=article