?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=B&rft.au=Gerard%2C+B&rft.aulast=Gerard&rft.atitle=Aerial+photography+to+determine+fertiliser+effects+on+pearl+millet+and+Guiera+senegalensis+growth&rft.title=Plant+and+Soil&rft.issn=0032-079X&rft.date=1999&rft.volume=210&rft.pages=167-177&rft.issue=2&rft.genre=article