https://open.overheid.nl/documenten/ronl-48b77cf7bdf0f91d4ed394ca2a37d2041bc50647/pdf
https://www.ips-journal.eu/topics/european-union/beware-the-low-hanging-fruit-5019/?utm_campaign=en_869_20210305&utm_medium=email&utm_source=newsletter
http://www.imf.org/external/np/seminars/eng/2015/secularstag/pdf/Venkateswaran.pdf
https://www.strategie.gouv.fr/sites/strategie.gouv.fr/files/atoms/files/fs-2020-point-de-vue-planification-juin.pdf