00305nam a2200109Ia 450000500170000000800410001708200150005810000170007324500530009026000440014330000080018720260225051014.0260224s9999||||xx |||||||||||||| ||und||  a338.17 UPT  aMartin Upton 0aAgricultural production economics & resource-use  aLondon: Oxfored University Press c1976  a357