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

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