1. § 23 EStG. (2022, September 12). Retrieved September 21, 2022, from https://www.gesetze-im-internet.de/estg/__23.html
2. Amaro, S., & Kharpal, A. (2018). EU reveals a digital tax plan that could penalize Google, Amazon and Facebook. CNBC. Retrieved September 21, 2022, from https://www.cnbc.com/2018/03/21/eu-reveals-a-digital-tax-plan-that-could-penalize-google-amazon-and-facebook.html
3. Audretsch, D. B. (2015). Everything in its place: Entrepreneurship and the strategic management of cities, regions, and states. Oxford University Press.
4. Bereitschaft, B. (2019). Are walkable places tech incubators? Evidence from Nebraska’s ‘Silicon Prairie’. Regional Studies, Regional Science, 6(1), 339–356. https://doi.org/10.1080/21681376.2019.1620631
5. Bliss, H. (2022). A list of natural resources of California. Retrieved September 20, 2022, from https://sciencing.com/a-list-of-natural-resources-of-california-13636253.html