00278nam a2200097Ia 4500008004100000082002600041245004600067260003500113300001000148650002200158140113s9999    xx            000 0 und d  a"631(338)""21"" 1997"  aPrecision agriculture in the 21st century  b"National academy press, 1997"  a149p.  aPrecision farming