00302nam a2200109Ia 4500082001900000100003700019245004000056260004400096300001500140500000500155700003200160  a338.1bH433.AP  aHeady, E. O. and Dillon, John L.  aAgricultural production functionsb  aIowabIowa State University Pressc1961  aviii, 667p  a  aDillon, John L. ; jt. auth.