Comparing difference set implementation - http://highlyscalable.wordpress.com/2011/12/29/ultimate-sets-and-maps-for-java-p1/

https://medium.freecodecamp.org/all-you-need-to-know-about-tree-data-structures-bceacb85490c

https://medium.com/basecs/finding-the-shortest-path-with-a-little-help-from-dijkstra-613149fbdc8e

Open address hash - https://www.andreinc.net/2021/11/08/a-tale-of-java-hash-tables