[1].Gerschenkron, Alexander, "Economic Backwardness in
Historical Perspective", A book of Essays, Cambridge,
Harvard University Press, USA, 1962.

[2].Romer, Paul M, "Why indeed in America, Theory, History
and the Origins of Modern Economic Growth", NBER
working paper series 5443, USA, 1996.
The Economist, "World in Figures", Profile Book Ltd, London
U.K, 2006.

[3].David Landes, "The Wealth and Poverty of Nations", WW
Norton & Company, USA, 1998.
Derived by the writer from several resources.

[4].James M.Utherback, "Mastering the Dynamics of
Innovation", Harvard Business School Press, USA, 1994.