https://www.hamiltonproject.org/assets/files/UnionsEA_Web_8.19.pdf
https://www.tasc.ie/assets/files/pdf/ensuring_good_future_jobs.pdf
http://visegradinsight.eu/app/uploads/2019/11/EaP-2030-Trends.pdf
https://www.baua.de/DE/Angebote/Publikationen/Berichte/F2398.pdf?__blob=publicationFile&v=3