https://smapse.com/why-is-there-still-no-bridge-from-europe-to-africa
https://en.wikipedia.org/wiki/Strait_of_Gibraltar
https://en.wikipedia.org/wiki/Strait_of_Gibraltar_crossing
https://www.viva.co.id/english/1480590-the-reason-why-no-bridge-between-the-continent-europe-and-africa
https://www.theparliamentmagazine.eu/news/article/why-building-a-fixed-link-between-europe-and-africa-matters
https://www.luxurytraveladvisor.com/transportation/will-a-tunnel-from-spain-to-africa-ever-be-built-and-who-would-use-it
https://www.newcivilengineer.com/latest/new-bridge-form-mooted-for-europe-africa-crossing-19-09-2018/
https://en.wikipedia.org/wiki/Channel_Tunnel
https://en.wikipedia.org/wiki/Rock_of_Gibraltar
https://www.atlasbig.com/en-us/countries-tourism-income