00380nam a2200121Ia 4500008004100000082002100041100002000062245005400082260007500136300001000211600001800221650001900239140224s9999    xx            000 0 und d  a631.5:658.513 L7  aElderen, E.Van.  aHeuristic strategy for scheduling farm operations  aWageningenbCentre for Agricultural Publishing and Documentationc1977  a217p.  aE.Van Elderen  aFarm operatons