00312nam a2200109Ia 450000500170000000800410001702000140005808200200007210000180009224500560011026000360016620250107154611.0241216s9999||||xx |||||||||||||| ||und||  a582603048  a338.109  13 ABB  aAbbott, J. C. 0aAgricultural economics and marketing in the tropics  aLondonbLongman Group Ltdc1979