I think it would be helpful if tags for specific electronics books could be created. People learning electronics often study from books and if they're having trouble, say with a specific circuit from a particular book, it would be helpful to subsequent users if the book tag could be used to narrow down search results to questions for that specific book. For example, if I'm having a problem with a circuit that occurs in the book "Make: Electronics" I get some search results that match, but many others that don't match because the words "make" and "electronics" are pretty generic.
This makes no sense as it would by definition fall under too localized. Books come and go, the popularity of those books come and go, and the popularity varies widely by region.
If someone has a question about something they see in a book, they should distill it down to a paragraph or so, probably with a quote from the relevant passage or scan of the schematic. Put the title and author name of the book in the question, and anyone that happens to bump into that same issue should be able to find the question well enough.