Perhaps you should try some spelling variations:
"resource research series" » "resources research series", "resource search series", "resonance research series", "resource research services", "resource research theories", "resource research service", "reforce research series"
"resource research studies" » "resources research studies", "resource search studies", "resonance research studies", "resource research study", "reforce research studies"
"source research series" » "source research services", "source research theories", "source research service", "sources research series", "force research series", "source search series"

Try widening your search to All Fields.

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 ("source research series"))) OR ("resource research studies")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"resource research series\") OR (\"source research series\"))) or (\"resource research studies\"))".
• Removing quotes may allow a broader search: (((( resource research series ) OR ( source research series ))) or ( resource research studies )).
• Adding a wildcard symbol may retrieve word variants: (((("resource research series") OR ("source research series"))) or ("resource research studies"))*.