Levin, Gregor (2004) Studying the effect of organic farming on rural landscapes: Issues of methodology and scale. Sixth International Farming Systems Association (IFSA) European Symposium., Villa Real, Portugal, April 4-7, 2004. In: Cristováo, Artur (Ed.) Proceedings of the Sixth European IFSA Symposium, European Farming and Society In Search of a New Social Contract - Learning to Manage Change, UTAD, Portugal, 2, pp. 325-334. *