Perhaps you should try some spelling variations:
"resource research series" » "resources research series", "resource search series", "source research series", "resource research services", "resource research theories", "resource research service"
"residual research series" » "residues research series", "resident research series", "residential research series", "residual research services", "residual research theories", "residual research service"
"residue research series" » "residues research series", "rescue research series", "resident research series", "residue research services", "residue research theories", "residue research service"
"residue research studies" » "residues research studies", "rescue research studies", "resident 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 ("residual research series"))) OR ("residue research studies")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"resource research series\") or (((((\"residue research series\") OR (\"residual research series\"))) or (\"residue research studies\"))))".
• Removing quotes may allow a broader search: (( resource research series ) or ((((( residue research series ) OR ( residual research series ))) or ( residue research studies )))).
• Adding a wildcard symbol may retrieve word variants: (("resource research series") or ((((("residue research series") OR ("residual research series"))) or ("residue research studies"))))*.