1. Schumpeter J. A., 1961. The Theory of economic development: An inquiry into profits, capital, credit, interest, and the business cycle, Oxford University Press, New York [N.Y.].
2. Brockhoff K., 1999. Produktpolitik, 4th ed., Stuttgart.
3. Gausemeier J., Ebbesmeyer P., and Kallmeyer F., 2001. Produktinnovation: Strategische Planung und Entwicklung der Produkte von morgen, Hanser, München.
4. Christensen C. M., 1997. The innovator's dilemma: When new technologies cause great firms to fail, Harvard Business School Press, Boston, Mass.
5. Porter M. E., 2011. Competitive advantage of nations: creating and sustaining superior performance, Simon and Schuster.