00271nam a2200097Ia 450000500170000000800410001708200140005810000230007224500350009526000430013020260224040958.0260224s9999||||xx |||||||||||||| ||und||  a631.1 EFF  aJ  Norman Efferson 0aPrinciples of farm management.  aNew York, Mc-Graw-Hill Book Co. c1953