1. A relief meter for soil cultivation studies;Kuppers;Neth. J. agric. Sci.,1957
2. Total pore-space estimations in freshly ploughed soil;Kuipers;Neth. J. agric. Sci.,1963
3. Effect of cultivations on the level of the surface of a soil;Wilton;J. agric. Engng. Res.,1964
4. A field measurement of total porosity and surface microrelief of soils;Burwell,1963
5. An integrating reliefmeter for soil tillage experiments;Van Ouwerkerk;J. agric. Engng Res.,1965