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Modern C is a nice one, and free to read at

https://hal.inria.fr/hal-02383654

You still might want to read that first, if you haven't.

K&R 2nd edition is ANSI C. It will run everywhere, but I think nowadays C99 is expected at least, along a book on BSD 4.4 and the infamous Advanced Programming in the Unix Environment.

But the K&R 2nd edition is ANSI C is perfect to begin with. 99% of what you see in the src will be enough to be understood with that background.

There might be better ones but maybe Effective C from No Starch press.