?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Bellof%2C+Prof.+Dr.+Gerhard&rft.aulast=Bellof&rft.aufirst=Gerhard&rft.date=2005&rft.title=Eine+%C3%83%C2%B6kologische+H%C3%83%C2%BChnermast+mit+%22100-%25-Bio-Futter%22+ist+m%C3%83%C2%B6glich&rft.genre=proceeding