https://piie.com/system/files/documents/2018-06-27-rosengren-presentation.pdf
https://opportunityinsights.org/wp-content/uploads/2020/05/tracker_paper.pdf
https://ec.europa.eu/competition/publications/reports/kd0419345enn.pdf
https://trade.ec.europa.eu/doclib/docs/2021/july/tradoc_159709.pdf