00306nam a2200109Ia 450000500170000000800410001708200140005810000240007224500490009626000430014530000080018820260225051013.0260224s9999||||xx |||||||||||||| ||und||  a338.1 RIT  aChristopher Ritson  0aAgricultural economics: Principles & policy   aLondon: Crossby Lookwood Staplesc1977  a409