1. Arora, A., Belenzon, S., Patacconi, A., and Suh, J. (2019). The Changing Structure of American Innovation: Some Cautionary Remarks for Economic Growth, National Bureau of Economic Research. WP 25893.
2. (2023, June 16). Key Factors Behind Productivity Trends in EU Countries, ECB Occasional Paper. 2021, No. 2021/268. Available online: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3928289.
3. Government-funded research increasingly fuels innovation;Fleming;Science,2019
4. Hünermund. A global decline in research productivity? Evidence from China and Germany;Boeing;Artif. Intell. Sci. Chall. Oppor. Future Res. Econ. Lett.,2020
5. (2023, October 10). Directorate-General for Research and Innovation, Science, Research and Innovation Performance of the EU 2022 Report. Available online: https://op.europa.eu/en/publication-detail/-/publication/52f8a759-1c42-11ed-8fa0-01aa75ed71a1/.