Perhaps you should try some spelling variations:
classical sources » classical studies, classical spaces
classical source » classic source, classical force, classical resources
classical charge » classical charged, classical chapter, classical chaos
sources library » resource library, studies library, series library
source library » source libraries, core library
classical core » classical codes, classical case, classical closed

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 sources library ) OR ( classical source library ))) OR ( ((classical core) OR (classical charge)) library )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( classical sources library ) or ( classical source library ))) or ( ((classical core) OR (classical charge)) library ))".
• Adding a wildcard symbol may retrieve word variants: (((( classical sources library ) or ( classical source library ))) or ( ((classical core) OR (classical charge)) library ))*.