l176.
For a discussion of the eco-efficiency of manual skills and advanced technology, relative to that of conventional industrial-scale systems, see Oliviero Bernardini and Riccardo Galli, “Dematerialization: Long Term Trends in the Intensity of Use of Materials and Energy”, Futures, vol 25, 4, 1993, pp 431–448. Their work is based on Wilfred Malenbaum (1978), World Demand for Raw Materials in 1985 and 2000.