Okay, I realize "profusion" might seem a bit overblown, but honestly, in C world (and in comparison to other languages), this is practically a publishing boom.
Not that I'm complaining; C was my first programming language (back some time in the mid-90s), and it's still my favorite. But I wonder why we're suddenly getting new books on it? The language itself hasn't undergone any substantial changes recently, and if anything, "memory safety" is all the rage -- a thing that C most assuredly is not.