1. Gyuricza, Cs., 2000, Effects of the conventional and conservational tillage systems on selected physical and biological parameters of soil. PhD thesis, SZIE Gödöllő (Hungarian with English summary) p. 148
2. Smith, S.T., T.C. Stoneman, C.V. Malcolm., 1969, Cultivation and traffic hardpan in Swan Valley vineyards. Western Australian Department of Agriculture Technical Bulletin No. 1.