1. Utility of motor-tractors for tillage purposes;Amos,1918
2. The effects of compaction of agricultural soils on soil fauna. I. Field investigations;Aritajat;Pedobiologia,1977
3. Traffic compaction of soil and tillage requirements;Arndt;J. Agric. Eng. Res.,1966
4. Deep and shallow ploughing in the rotation;Birecki;Grundförbättring,1966
5. Persistence of subsoil compaction in a mollisol;Blake;Soil Sci. Soc. Am. J.,1976