In the section 3.2.2 [Automatic memory management](https://craftinginterpreters.com/the-lox-language.html#automatic-memory-management), the side information refering to the Unified theory of Garbage Collector, is broken. `For lots more on this, see “A Unified Theory of Garbage Collection” (PDF).` Need to replace [https://researcher.watson.ibm.com/researcher/files/us-bacon/Bacon04Unified.pdf](https://researcher.watson.ibm.com/researcher/files/us-bacon/Bacon04Unified.pdf) with [https://courses.cs.washington.edu/courses/cse590p/05au/p50-bacon.pdf](https://courses.cs.washington.edu/courses/cse590p/05au/p50-bacon.pdf) .