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

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 ((("residue research series") OR ("resident research series"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"rescue research studies\") OR (\"resource research studies\"))) or (((\"residue research series\") or (\"resident research series\"))))*".
• Removing quotes may allow a broader search: (((( rescue research studies ) OR ( resource research studies ))) or ((( residue research series ) or ( resident research series ))))*.