1. Babbie, E.R. 2016. The practice of social research. 14th ed. Cengage Learning, Boston, Mass.
2. Becker, P. 2002. Corporate foresight in Europe: a first overview. Institute for Science and Technology Studies, University of Bielefeld, Bielefeld.
3. Breschi, S., and Malerba, F. 1997. Sectoral innovation systems: technological regimes, Schumpeterian dynamics, and spatial boundaries. In Systems of innovation: technologies, institutions and organizations. Edited by C. Edquist. Systems of Innovation: Technologies, Institutions, and Organizations, Pinter, London. pp. 130–156.
4. Internal capabilities and external knowledge sources: complements or substitutes for innovative performance?
5. Chesbrough, H. 2003a. Open Innovation: the new imperative for creating and profiting from technology. Harvard Business School Press, Boston, Mass.