
https://www.lobbycontrol.de/wp-content/uploads/LobbyControl-Jahresbericht_2022-2023.pdf

https://www.census.gov/content/dam/Census/library/publications/2019/demo/p60-266.pdf

https://www.globallegalinsights.com/practice-areas/bribery-and-corruption/global-legal-insights—bribery-and-corruption/germany