1. Ewald Wollny — A pioneer in soil and water conservation research;Baver,1938
2. Soil Physics;Baver,1956
3. Raindrop energy and soil erosion;Ellison;Emp. J. Exp. Agric.,1952
4. Rainfall parameters and a cover model to predict runoff and soil loss from grazing trials in the Rhodesian sandveld;Elwell,1974