Mad C Skillz OEMG

I want to jump to the next level in C. I'm a quite skilled programmer for what I do, know the whole K&R but I feel like I miss something, especially about those weird techniques proPROgrammers use in OS dev and related. Suggested readings?

>>52
Plan 9 from Bell Labs is a distributed operating system, primarily used for research. It was developed as the research successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002.