?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=A&rft.au=Buerkert%2C+A&rft.aulast=Buerkert&rft.atitle=Multi-site+time-trend+analysis+of+soil+fertility+management+effects+on+crop+production+in+sub-Saharan+West+Africa&rft.title=Experimental+Agriculture&rft.issn=0014-4797&rft.date=2002&rft.volume=38&rft.pages=163-183&rft.issue=2&rft.genre=article