00343nam a2200109Ia 450000500170000000800410001702000150005805000170007310000190009024501030010926000210021220251229085413.0251229s9999    xx            000 0 und d  a0813805406  aHD 1425  .H4  aHeady, Earl O. 0aEconomic Models and Quantitative  Methods for Decisions and Planning in Agriculture.cEarl O Heady  aIOWAbAMESc1971