5Schulze Lammers,Peter; Sun,Yurui..Combined sensor for simultaneous investigation of cone index and soil water content[J].ASAE Annual International Meeting,2004.
6Najm,Amer; Sidahmed,Moatasim M..Cone index before and after plowing of stony clay soil as a function of depth and moisture[J].2007 ASABE Annual International Meeting.Technical Papers,2007.
7LaMontagne,Jalene M.; Peters Susan; Boutin Stan.A visual index for estimating cone production for individual white spruce trees[J].Canadian Journal of Forest Research,2005.
8Hummel,d.W.; Ahmad,I.S.; Newman,S.C.; Sudduth,K.A.; Drummond,S.T..Simultaneous soil moisture and cone index measurement[J].Transactions of the American Society of A-gricultural Engineers,2004.
9M.R.Mosaddeghi;A.Hemmat; M.A.Hajabbasi;A.Alexandrou.Pre-compression stress and its relation with the physical and mechanical properties of a structurally unstable soil in central Iran[J].Soil & Tillage Research,2003(70):53-64.
10Bekker,M G.Off-the-road locomotion[M].Ann Arbor:The University of Michigan Press,1960.