1. Arvidsson, J., 1997. Early sowing—a reduced tillage system for spring sowing. Field experiments 1992–1996. Report No. 92. Reports from the Division of Soil Management, Swedish University of Agricultural Sciences, Uppsala, 45 pp. (in Swedish with English summary).
2. Modeling of wheat imbibition and germination as influenced by soil physical properties;Bouaziz;Soil Sci. Soc. Am. J.,1989
3. Soil tillage for crop production and for protection of soil and environment: a Scandinavian viewpoint;Håkansson;Soil Till. Res.,1994
4. Håkansson, I., 2000. Methods for characterizing the tillage zone—some comments on the need for new development. In: Proceedings of the 14th International Conference of the International Soil Tillage Research Organization (ISTRO), Fort Worth, TX (on CD-ROM).
5. Håkansson, I., von Polgár, J., 1976. Model experiments into the function of the seedbed. I. The seedbed as a protective layer against drought. Report No. 46. Reports from the Division of Soil Management, Agricultural College of Sweden, Uppsala, 52 pp. (in Swedish with English summary).