00558nam a2200193Ia 4500001001000000003000500010008004100015010001100056040000900067100001700076245009900093260005000192300000900242440003300251650002200284650002000306650002100326700001700347Para_6668CHAP220125s1977    xx            000 0 und d  a205515  cCHAP  aZwick, R. W.  aIntegrated control of pear Psylla in Oregon's Hood River Valley /c R.W. Zwick and G.J. Fields  aCorvallis :b Agricultural Experiment Station  a8 p.  aCircular of information; 660  aControl de Plagas  aPera x plagas   aPsylla pyricola   aFields, G.J.