1. ABS (2018) Australian Bureau of Statistics. Available at:
https://www.abs.gov.au
. Accessed 5 Sept 2018
2. Barnett H (1979) Scarcity and growth revisited. In: Smith VK (ed) Scarcity and growth reconsidered. Johns Hopkins University Press for Resources for the Future, Baltimore
3. Barnett H, Morse C (1963) Scarcity and growth: the economics of natural resource availability. Johns Hopkins University Press for Resources for the Future, Baltimore
4. BHP (2014) Focusing on operating and capital productivity. Available at:
https://www.bhp.com/media-and-insights/reports-and-presentations/2014/11/focusing-on-operating-and-capital-productivity
. Accessed September 2018
5. BLS (2018) US Bureau of Labor Statistics. Available at:
https://www.bls.gov
. Accessed 5 Sept 2018