00273nam a22001217a 4500020001800000082001500018100003100033245004800064250000600112260000900118300000800127650001600135  a9789388812900  a630bWAL/F  aWalia , S.S aWalia , U.S   aFarming system and sustainable agriculture   a1  c2025  a336  aAgriculture