1. Reconsidering power in international relations;Akgül;Chinese Political Sci. Rev.,2020
2. Measuring Space Power: A Theoretical and Empirical Investigation on Europe;Aliberti,2019
3. Andy, 2022. How many Earth observation satellites are orbiting the planet in 2021, https://www.pixalytics.com/eo-sats-2021/ (accessed 14 May, 2023).
4. Go Astronomy, 2022. Spaceports & Launch Sites, https://www.go-astronomy.com/space-ports.php (accessed 14 May, 2023).
5. The power of nations: Measuring what matters;Beckley;Int. Secur.,2018