Perhaps you should try some spelling variations:
"resources research series" » "research research series", "reservices research series", "resciences research series", "redevices research series", "resources research services", "resources research theories", "resources research studies"
"sources research series" » "services research series", "sciences research series", "devices research series", "sources research services", "sources research theories", "sources research studies"

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