1. Heterogeneity of soil of agricultural land in relation to soil sampling;Leo;J. Agric. Food Chem.,1963
2. Soil variability - a serious problem in soil site studies in the Northeast;Mader,1963
3. The soils of the Mendip District of Somerset;Findlay,1965
4. Variation of soil morphological properties within Miami, Celina and Crossby mapping units in West-Central Ohio;Wilding,1965
5. Soil sampling in relation to soil heterogeneity;Hammond,1958