- https://www.slideshare.net/jackfoxy/introduction-to-the-lambda-calculus
- https://www.slideshare.net/DiegoMendona3/lambda-calculus-29802319
- https://www.slideshare.net/MahsaSeifikar/lambda-calculus-57240548
- https://speakerdeck.com/glebec/lambda-as-js-or-a-flock-of-functions-combinators-lambda-calculus-and-church-encodings-in-javascript
- http://www-verimag.imag.fr/~iosif/LogicAutomata07/lambda-calculus-slides.pdf
- https://www.jtolio.com/2017/03/whiteboard-problems-in-pure-lambda-calculus/
- https://www.dropbox.com/s/i0qgfoye6artcp8/untyped_lambda.pdf?dl=0
- https://medium.com/@maiavictor/the-abstract-calculus-fe8c46bcf39c
- http://blog.klipse.tech/lambda/2016/07/24/lambda-calculus-1.html
- https://www.youtube.com/watch?v=3VQ382QG-y4&t=1251s