Perhaps you should try some spelling variations:
"pressure research series" » "present research series", "pressure release series", "pressure research services", "pressure research studies", "pressure research summaries"
"rescue research theories" » "rescue research theory", "rescue research themes", "rescue research topics", "rescue search theories", "issue research theories", "response research theories"
"resource research theories" » "resource research theory", "resource research themes", "resource research topics", "resources research theories", "resource search theories", "source research theories"
"residue research service" » "residues research service", "residual research service", "resident research service", "residue search service", "residue research overview", "residue research section"
"tissue research series" » "issues research series", "disease research series", "tissue research services", "tissue research studies", "tissue research summaries"

You may be able to get more results by adjusting your search query.

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