Perhaps you should try some spelling variations:
classical source » classical sources, classic source, classical force
source library » resource library, source libraries
classical core » classical codes, classical case, classical charge
core library » code library, case library, core libraries

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: (( classical source library ) OR ( classical core library )).
• Adding a wildcard symbol may retrieve word variants: (( classical source library ) or ( classical core library ))*.