1. Aspects of Precision Agriculture
2. The State of Site Specific Management for Agriculture
3. Goolsby , D. A. Coupe , R. C. Markovechick , D. J.Distribution of Selected Herbicides and Nitrate in the Mississippi River and Its Tributaries. April Through June, 1991; U.S. Geological Survey Water Resources Investigation Report , 1991 ; 91 – 163 .
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