1. F. Blomsma, and G. Brennan, J. Industrial Ecology 21, 603 (2017).
2. W. McDonough and M. Braungart, Cradle to cradle, remaking the way we make things, (North Point Press, New York, 2002).
3. World Bank http://blogs.worldbank.org/prospects/category/tags/historical-commodity-prices (2013) (accessed on 1 September 2017).
4. McKinsey Quarterly, February (2014).
5. M. F. Ashby, Materials and Sustainable Development, (Butterworth Heinemann. Oxford, 2016).