It is actually one of the nicest introduction to what Prolog is (not to how to use it).
I asked Dr Colmerauer a few years ago if the source code (apparently largely in Fortran) for the original Prolog interpreter still exists, but his belief is that it is lost. :(
Unfortunately he passed away in 2017.
RIP. A sad thing to hear.
I love the illustrations under the Prolog II heading, especially the parse tree drawn on a branch with leaves.
I studied AI back when Prolog was predominantly used in European AI research and I still have a soft spot for the language, even if I immediately stopped using it on graduation and wrote video games in C