00260nam a2200097Ia 450000500170000000800410001705000150005810000180007324500310009126000400012220251229192456.0251229s9999    xx            000 0 und d  aSB 185 .R3  aRather, H. C. 0aField crops .cH. C Rather  aLondonb Mcgraw-hill  book coc1942