
https://www.wto.org/english/thewto_e/whatis_e/tif_e/understanding_e.pdf

https://www.lobbycontrol.de/wp-content/uploads/gaslobby-studie-lobbycontrol.pdf

http://www.cbi.org.uk/index.cfm/_api/render/file/?method=inline&fileID=7C026F7C-746E-4795-90EFCC69B2FB6756