00281nam a2200109Ia 450000500170000000800410001708200120005810000170007024500360008726000400012330000080016320260224040926.0260224s9999||||xx |||||||||||||| ||und||  a632 ENN  aEnnis, W.B.  0aIntroduction to crop protection  aAmerican: Society of Agronomyc1979  a524