The links at [appendix.tex:L120](https://github.com/fabriziotappero/Free-Range-VHDL-book/blob/master/appendix.tex#L120) and [appendix.tex:L121](https://github.com/fabriziotappero/Free-Range-VHDL-book/blob/master/appendix.tex#L121) are broken.
The links at appendix.tex:L120 and appendix.tex:L121 are broken.