The bibliography section should include references actually used Furthermore its section heading should be References as per Wikipedia Manual of Style 28headings 29 Standard headings and ordering and inferred by Wikipedia Cite sources How to cite sources Being out of print does not mean that it is neither verifiable nor accessible The book mentioned above does not seem to be too specialised for this article particularly if it was actually used as a reference Need to check with the editor who added the reference as to what they used from the book