Natural Capital and Sustainable Development
Abstract: A minimum necessary condition for sustainability is the maintenance of the total natural capital stock at or above the current level. While a lower stock of natural capital may be sustainable, society can allow no further decline in natural capital given the large uncertainty and the dire consequences of guessing wrong. This “constancy of total natural capital” rule can thus be seen as a prudent minimum condition for assuring sustainability, to be relaxed only when solid evidence can be offered that it is safe to do so. 
Knowledge systems for sustainable development
The challenge of meeting human development needs while protecting the earth’s life support systems confronts scientists, technologists, policy makers, and communities from local to global levels. 
Characterizing and Measuring Sustainable Development
Sustainable development has broad appeal and little specificity, but some combination of development and environment as well as equity is found in many attempts to describe it. However, proponents of sustainable development differ in their emphases on what is to be sustained, what is to be developed, how to link environment and development, and for how long a time. 
Community Participation and Sustainable Development in the Niger Delta
The paper examined community participation and sustainable development in the Niger Delta. The research question addressed the extent at which sustainable development of the Niger Delta and improved welfare of oil producing communities is dependent on their participation in the design and execution of community projects. 
Sustainable Development of Tourism in Semnan City, Using the SWOT Analysis Model
Tourism is a complex activity that is related to different sectors of society and economy. Nowadays, the role and importance of this industry is main factor of every developed country, so they are trying to maximize utilization of the industry. 
 Costanza, R. and Daly, H.E., 1992. Natural capital and sustainable development. Conservation biology, 6(1), pp.37-46.
 Cash, D.W., Clark, W.C., Alcock, F., Dickson, N.M., Eckley, N., Guston, D.H., Jäger, J. and Mitchell, R.B., 2003. Knowledge systems for sustainable development. Proceedings of the national academy of sciences, 100(14), pp.8086-8091.
 Parris, T.M. and Kates, R.W., 2003. Characterizing and measuring sustainable development. Annual Review of environment and resources, 28(1), pp.559-586.
 Agwu, M. O. (2013) “Community Participation and Sustainable Development in the Niger Delta”, Journal of Education, Society and Behavioural Science, 3(1), pp. 33-46. doi: 10.9734/BJESBS/2013/2392.
 Daraei, M. and Rezazadeh, M. (2014) “Sustainable Development of Tourism in Semnan City, Using the SWOT Analysis Model”, Journal of Scientific Research and Reports, 3(16), pp. 2180-2196. doi: 10.9734/JSRR/2014/11234.