1. E. Ginzberg: The mechanization of work, Sci. Am. 247(3), 66–75 (1982)
2. US Bureau of the Census: Value of Construction Put in Place – Seasonally Adjusted Annual Rate (Luscensus, Washington 2006), available at: http://www.census.gov/
3. Bureau of Labor Statistic: Industry at a Glance, NAICS 23: Construction (US Department of Labor, Washington 2006), available at: http://www.bls. gov/iag/construction.htm
4. US Bureau of the Census: Statistics of U.S. Businesses (Luscensus, Washington 2006), available at: http://www.census.gov/csd/susb/
5. European Communities: Europe in Figures – Eurostat Yearbook 2005 (European Commission, Brussels, 2005), available at: http://epp.eurostat.ec. europa .eu/cache/ITY_OFFPUB/KS-CD-05-001/EN/KS-CD-05-001-EN.PDF