Need to read on Design Patterns

If I want to understand the code... I have to finished it by the end of this week!!!

There are a lot of design patterns used in the software, which is amazing! You can see how these patterns are really used in the system and make the correlation between different modules much less or make the implementation much more convinient.

Patterns I have seen:
Abstract Factory, Singleton, Facade, Build, Command, etc.

I will see more for sure...