https://www.esri.ie/sites/default/files/media/file-uploads/2020-01/Slides_1.pdf
http://ec.europa.eu/newsroom/just/item-detail.cfm?item_id=607452
https://www.ons.gov.uk/employmentandlabourmarket/peopleinwork/earningsandworkinghours/articles/contractsthatdonotguaranteeaminimumnumberofhours/may2017
https://theconversation.com/the-gig-economy-is-nothing-new-it-was-standard-practice-in-the-18th-century-81057