Which sources do you recommend to learn C ?

Question

I need to answer some questions to get an internship. Questions rely on C knowledge so i really need to improve myself in C.

Answer 1

In this code i inserted PDF resources (totally free) for C / C++

>> https://code.sololearn.com/W8iMGXTusS8V/?ref=app

Bye. ^_^

Answer 2

follow instructions on youtube.

Answer 3

Thank you very much!