http://researchbriefings.files.parliament.uk/documents/CBP-7484/CBP-7484.pdf
http://www.ilo.org/wcmsp5/groups/public/—dgreports/—dcomm/—publ/documents/publication/wcms_537982.pdf
https://www.fastcompany.com/90556370/this-is-the-most-in-demand-skill-in-job-listings-right-now
https://www.ilo.org/legacy/english/inwork/cb-policy-guide/declarationofPhiladelphia1944.pdf