UNITY

How UNITY became the main Game Engine in the World
https://techcrunch.com/2019/10/17/how-unity-built-the-worlds-most-popular-game-engine/

History of UNITY
http://web.wpi.edu/Pubs/E-project/Available/E-project-030614-143124/unrestricted/Haas_IQP_Final.pdf

UNITY TIMELINE
https://populartimelines.com/timeline/Unity-Technologies

UNITY VS GODOT
https://www.gamedesigning.org/engines/unity-vs-godot/

GAME ENGINE BASICS (check the following pages)
https://www.studytonight.com/3d-game-engineering-with-unity/game-engine

UNITY VS UNREAL
https://hackr.io/blog/unity-vs-unreal-engine
https://circuitstream.com/blog/unity-vs-unreal/