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2. Christensen, C. M. and Raynor, M. E. 2003. The Innovator's Solution: Creating and Sustaining Successful Growth. Boston: Harvard Business School Press, p. 73.
3. 2003. Improving New Product Development Performance and Practices. Houston: APQC International Benchmarking Clearinghouse, pp. 18–19.
4. 2003. Improving New Product Development Performance and Practices. Houston: APQC International Benchmarking Clearinghouse, pp. 25–26.