1. Compaction and subsoiling effects on corn growth and soil bulk density;Abu-Hamdeh;Soil Science Society of America Journal,2003
2. D497.4: Agricultural Machinery Management Data;ASAE Standards,2003
3. S313.3: Soil Cone Penetrometer;ASAE Standards,2004
4. Comparison of the energy requirements of an experimental plow, a moldboard plow and a disk plow;Celik;Philippine Agricultural Science,2007
5. Spatial variation of soil physical properties: a precursor to precision tillage;Fulton,1996