Obviously, there's the iconic K&R, which some people don't like for its terseness. I loved it - pure and to the point. However, the second book that made a huge impact on me was "Reusable Data Structures For C" by Roger Sessions. If you internalize these two books you'll be a highly competent C programmer. https://www.amazon.com/Reusable-Data-Structures-Prentice-hal...