1. Studies in Soil Cultivation;Keen;Jour. Agric. Sci.,1925
2. Studies in the Physical Properties of Soils — Mechanical Properties Concerned in Cultivation;Haines;Jour. Agric. Sci.,1923
3. A Study of the Plow Bottom and its Action upon Furrow Slice;White;Trans. A.S.A.E.,1918
4. Dynamic Properties of Soil Affecting Implement Design;Nichols;Agric. Eng.,1930
5. The Dynamic Properties of Soil IV. A Method of Analysis of Plow Moldboard Design Based on Dynamic Properties of Soil;Krummer;Agric. Eng.,1932