Great C# Books for strong OOP foundation

Hello,
My Unity C# skills are at a basic to decent level which is highly vague and subjective so here is an example of a personal project I worked on so you have an idea of my skill level:

I feel I lack a foundation of OOP as I am just self-taught through unity tutorials so a lot of the time, I know something is meant to work in Unity more often than I understand something is meant to work if that makes sense. This usually results me in very much depending on YouTube tutorials and forums to tackle anything new which is very frustrating.

Therefore I am seeking to strengthen my foundation through C# books.
Which C# books would you recommend to give me this foundation?
From my research it seems, there are several like C# in a nutshell or Concurrency with C# or Learning C# by Developing Games with Unity 2020. Although I'm not sure if the last book mentioned will give me that foundation.

Thanks for any help/tips/suggetsions

CARD00R

 

Just be careful while learning it to not get too caught up in it. Since Unity uses C# you can structure your games in an object-oriented manner but the engine is very much designed with a data-oriented design (DOD) approach and if you decide to eventually pick up Unity's DOTS you will be leaving most of OOP behind.

 

I ordered number 4 in your list last week, it's coming from WOB.com tomorrow.