
https://theconversation.com/dna-says-youre-related-to-a-viking-a-medieval-german-jew-or-a-1700s-enslaved-african-what-a-genetic-match-really-means-222833

https://www.cps.org.uk/files/reports/original/201001000814-CPSUPWARDLYMOBILE2.pdf

https://towardsdatascience.com/analyzing-global-literacy-rates-data-in-r-88062f813ad2