title: How to study programming with C language
body: <p>I am using only C for 5 years. 
  So I am sure that I know C grammar, but I have no idea how to advance programming skills.</p>
  
  <p>There are many books for modern languages (such as C++, Java) to study programming skills like the refactoring or pattern, software architecture. But no book is written with C language.
  The book author say that his/her book is not language-dependent, but I don't think so.</p>
  
  <p>How can I advance my programming skills? I have to study modern language and read the books?
  Are there books about software design or programming skill written with C?</p>