00498nam a2200181Ia 4500001001000000003000500010008004100015010001100056040000900067245005300076260005600129300001000185440003000195650002400225650002600249650002000275700002100295Para_6897CHAP220125s1978    xx            000 0 und d  a205213  cCHAP  aPear production /c by Max W. Williams [et. al.]  aWashington :b Science and Education Administration  a53 p.  aAgriculture handbook; 526  aPera x crecimiento  aPera x enfermedades   aPera x plagas   aWilliams, Max W.