https://www.quora.com/How-are-cracked-versions-of-software-created-and-why-are-developers-not-able-to-prevent-it

https://www.quora.com/What-is-the-most-sophisticated-piece-of-software-code-ever-written

https://www.quora.com/What-are-the-main-differences-between-a-principal-component-analysis-and-a-factor-analysis

https://peerj.com/articles/5518/

https://realpython.com/python-pandas-tricks/

https://github.com/trekhleb/learn-python/blob/master/README.md