Perhaps you should try some spelling variations:
"resource research series" » "resources research series", "source research series", "resonance research series", "resource research services", "resource research theories", "resource research studies"
"resource search theories" » "resources search theories", "resource sears theories", "resource scarce theories", "resource research theories", "resource earth theories", "resource search theory"

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: (("resource research series") OR ("resource search theories")).
• Removing quotes may allow a broader search: (( resource research series ) or ( resource search theories )).
• Adding a wildcard symbol may retrieve word variants: (("resource research series") or ("resource search theories"))*.