https://www.brookings.edu/wp-content/uploads/2016/07/Full-Report.pdf
https://www.etui.org/sites/default/files/2025-06/Non-standard%20and%20precarious%20work%20across%20Europe_2025.pdf
https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef20001en.pdf
http://ec.europa.eu/newsroom/just/item-detail.cfm?item_id=607452