00471nam a22001457a 4500003000400000005001700004008004100021040000800062082002100070100001900091245009500110260003900205300001000244650007100254OSt20220520093750.0030206s2002 ck 000 0 spa d cOSt04221a333.76bB466 aBenor, Daniel 00aAgricultural extension :cDaniel Benor; James Q. HarrisonbThe training and visit system / aWashington: bWorld Bank, c1977. a55 p.042LEMBxAGRICULTURA xEXTENCIÓN AGRÍCOLA xQUÍMICA AGRICOLA