?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=R&rft.au=Trippa%2C+R&rft.aulast=Trippa&rft.atitle=Policies+for+African+seed+enterprise+development+&rft.title=Food+Policy&rft.date=2001&rft.volume=26&rft.pages=147-161&rft.issue=2&rft.genre=article