?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=P&rft.au=Pathak%2C+P&rft.aulast=Pathak&rft.atitle=Long-term+effects+of+management+systems+on+crop+yield+and+soil+physical+properties+of+semi-arid+tropics+of+Vertisols&rft.title=Agricultural+Sciences&rft.issn=2156-8553&rft.date=2011&rft.volume=2&rft.pages=435+-442+&rft.issue=4&rft.genre=article