Perhaps you should try some spelling variations:
"resource research series" » "resources research series", "source research series", "resource search series", "resource research services", "resource research theories", "resource research service"
"residue research series" » "residues research series", "residual research series", "rescue research series", "residue research services", "residue research theories", "residue research service"
"residue research studies" » "residues research studies", "residual research studies", "rescue research studies", "residue research study"

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