Perhaps you should try some spelling variations:
specialist libraries » specialist librarians, special libraries
spectral libraries » special libraries, several libraries
specific libraries » special libraries, scientific libraries, specific injuries

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: academic & ((((((specialist libraries) OR (spectral libraries))) OR (spectral library))) OR (specific libraries)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "academic & ((((((specialist libraries) OR (spectral libraries))) or (spectral library))) or (specific libraries))".
• Adding a wildcard symbol may retrieve word variants: academic & ((((((specialist libraries) OR (spectral libraries))) or (spectral library))) or (specific libraries))*.