Which academic sources would you recommend on this topic?

I've checked the sources from that book and they seem legit, including papers and articles[1]. Besides, the reviews of that book are very positive [2].

[1]: http://guides.skylinecollege.edu/c.php?g=279172&p=1861295 [2]: https://www.amazon.co.uk/Outliers-Story-Success-Malcolm-Glad...