Learn Haskell Source:

http://www.pjb.com.au/laska/play_laska.html

https://mail.haskell.org/pipermail/beginners/2009-February/000876.html

https://learnxinyminutes.com/docs/haskell/

https://www.haskell.org/tutorial/arrays.html

http://learnyouahaskell.com/making-our-own-types-and-typeclasses