?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Zeltner%2C+Esther&rft.aulast=Zeltner&rft.aufirst=Esther&rft.title=How+should+a+hen+run+be+structured+so+that+it+is+used+evenly+by+laying+hens+%3F&rft.date=2004&rft.genre=proceeding