I have seen many times these type of explanation were people addressed only page number of a book.
What should I do during a review? Should I flag answers as low quality or not an answer or skip?
Ask the answerer in a comment to expand their answer a bit, and explain that the idea of the site is that in general an answer is not just a link or a reference to a source that gives an actual answer. Yet, at least for the time being, I would let the answer stand; it does appear to provide some potentially useful information (the reference is quite precise, with page numbers even).
The above applies especially in this case, where the answer was given by a new user who could not comment (I think the information given, would be a perfectly good comment) and they may very well not be familiar with the standards of the site.