1. Bawden, R.J., 1995, Systemic Development: A Learning Approach to Change, unpublished occasional paper #1 Centre for Systemic Development.
2. Beck, U., 1992, Risk Society: Towards a New Modernity, Translation by Mark Ritter, Sage Publications, London.
3. Douglass, G.K., 1984, The Meanings of Agricultural Sustainability, in: Agricultural Sustainability in a Changing World Order (G.K. Douglass, ed.), Westview Press, Boulder.