00495nam a2200181 a 450000100080000000500110000800800410001910000170006024500460007726000370012330000100016065000160017065000270018665000350021365000280024870000210027670000160029710016892014-02-22       1999    bl uuuu     u00u1 u    #d1 aPETERSEN, C.  aFarming systems trialbthe first 15 years  aKutztown, PA (USA): Rodalec1999  a40 p.  aAGRICULTURA  aEXPLOTACIONES AGRARIAS  aINSTITUCIONES DE INVESTIGACION  aSISTEMAS DE EXPLOTACION1 aDRINKWATER, L.E.1 aWAGONER, P.